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COVID-19

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COVID-19
Disease Issues Administering Vaccines
Vaccine Recommendations Scheduling Vaccines
Vaccine Products Contraindications and Precautions
COVID-19 Vaccines for Children under 12 Years Vaccine Safety
COVID-19 Vaccines for Adolescents and Adults Storage and Handling
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This page was last updated on September 8, 2022. Guidance from CDC about COVID-19 vaccines may be updated frequently. For questions about guidance issued after this date, readers are referred directly to the Centers for Disease Control and Prevention (CDC) Use of COVID-19 Vaccines in the United States Interim Clinical Considerations: www.cdc.gov/vaccines/covid-19/clinical-considerations/covid-19-vaccines-us.html.

For a comprehensive collection of COVID-19 tools and resources, visit Immunize.org's Vaccines: COVID-19 main page: www.immunize.org/covid-19. For alerts about new Immunize.org or CDC COVID-19 resources, subscribe to our weekly newsletter, IZ Express.
Disease Issues
What is COVID-19?
COVID-19 is the name given to the disease caused by infection with the SARS-CoV-2 coronavirus. This virus was first detected as a cause of human illness in late 2019 in Wuhan, China, and triggered a global pandemic that began in 2020. The virus is thought to spread mainly from person to person through respiratory droplets produced when an infected person coughs, sneezes, or talks. These droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs. Some people who are infected have no symptoms of illness, while the severity of symptomatic illness ranges from mild to life-threatening. Older adults and people of any age with underlying medical conditions are at higher risk for severe illness.
The incubation period after exposure ranges from 2–14 days, with an average of about 5 days. People with COVID-19 are generally considered infectious up to 48 hours before symptom onset through 10 days after onset, though people with severe illness may be infectious longer. Symptoms may include fever or chills, cough, shortness of breath or difficulty breathing, fatigue, muscle or body aches, headache, new loss of taste or smell, sore throat, congestion or runny nose, nausea or vomiting, and diarrhea.
Where can I find answers to more clinical questions about COVID-19 disease, diagnosis, treatment and care of patients?
The CDC has assembled clinical questions and answers at this site: www.cdc.gov/coronavirus/2019-ncov/hcp/faq.html.
Vaccine Recommendations Back to top
Where can I find current COVID-19 vaccine recommendations?
The CDC's Advisory Committee on Immunization Practices (ACIP) has published recommendations for all COVID-19 vaccines that have received Emergency Use Authorization (EUA) or licensure from the federal Food and Drug Administration (FDA). ACIP and the CDC update vaccination recommendations frequently. Changes in CDC recommendations may be issued without an ACIP meeting or vote. All ACIP COVID-19 vaccine recommendations that have been published by CDC in MMWR can be accessed here: www.cdc.gov/vaccines/hcp/acip-recs/vacc-specific/covid-19.html. The current recommended COVID-19 vaccination schedules for each age group are available here: www.cdc.gov/vaccines/covid-19/downloads/COVID-19-immunization-schedule-ages-6months-older.pdf.
In addition to published ACIP recommendations for the use of these vaccines, CDC maintains a website with critical interim clinical considerations for vaccination of eligible recipients: www.cdc.gov/vaccines/covid-19/clinical-considerations/covid-19-vaccines-us.html. This site is updated within days of any change to CDC recommendations.
Who is recommended to receive COVID-19 vaccines?
All people age 6 months and older in the United States are recommended to receive an age-appropriate COVID-19 vaccination series. CDC's recommended schedule for each age group is available here: www.cdc.gov/vaccines/covid-19/downloads/COVID-19-immunization-schedule-ages-6months-older.pdf.
What is the current booster dose recommendation for COVID-19?
As of September 1, 2022, ACIP recommends that all people age 12 years and older who have completed a COVID-19 vaccination primary series with any monovalent COVID-19 vaccine (Pfizer-BioNTech, Moderna, Novavax, or Janssen) should receive an age-appropriate bivalent COVID-19 mRNA vaccine at least 2 months following their most recent COVID-19 vaccination. The bivalent mRNA vaccines (Pfizer-BioNTech or Moderna) help the immune system target the spike protein of the ancestral (original) strain, in addition to the spike protein of the more recently circulating Omicron BA.4/BA.5 subvariants.
Monovalent COVID-19 vaccines continue to be authorized and recommended for use as primary series vaccinations at all ages; however, as of September 1, 2022, monovalent COVID-19 vaccines are not authorized for use as a booster vaccine in any person age 12 years or older.
Children ages 5 through 11 years who received a Pfizer-BioNTech vaccine primary series should receive a Pfizer-BioNTech monovalent booster dose (the same formulation as the primary series) at least 5 months after completion of the routine 2-dose primary series if immunocompetent, or at least 3 months after administration of the additional primary series dose if moderately or severely immunocompromised.
Please refer to CDC's At-A-Glance COVID-19 Vaccination Schedules document for the most current recommended booster dose schedules by age and product type: www.cdc.gov/vaccines/covid-19/downloads/COVID-19-vacc-schedule-at-a-glance-508.pdf.
For full details, please review the recommendations information available at CDC's web page, "Use of COVID-19 Vaccines in the United States Interim Clinical Considerations": www.cdc.gov/vaccines/covid-19/clinical-considerations/covid-19-vaccines-us.html.
I know that the authorized and recommended use of Janssen COVID-19 is now limited to certain individuals. Who may receive the Janssen COVID-19 Vaccine?
There is limited availability of Janssen vaccine in the United States. Janssen COVID-19 Vaccine is authorized to prevent COVID-19 in individuals 18 years of age and older for whom other FDA-authorized or approved COVID-19 vaccines are not clinically appropriate, and individuals 18 years of age and older who elect to receive it because they would otherwise not receive a COVID-19 vaccine for reasons of choice or due to inability to access other options. For most individuals, the Janssen COVID-19 vaccine is authorized and recommended as a single primary series dose; a bivalent mRNA booster vaccine dose is recommended at least 2 months following the primary dose of Janssen vaccine. Individuals who are moderately or severely immunocompromised should receive an additional monovalent mRNA vaccine at least 4 weeks after the Janssen dose, followed by the bivalent mRNA vaccine booster at least 2 months after the monovalent mRNA dose.
All people who elect to receive a Janssen COVID-19 vaccine booster should be informed about the risk and symptoms of thrombosis with thrombocytopenia syndrome (TTS) that could occur after vaccination (typically within 2 weeks after receipt) and the need to seek immediate medical care should such symptoms develop at any time.
For further details concerning the CDC's recommendations for Janssen vaccine visit www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us-appendix.html#appendix-a.
Should people who have had COVID-19 illness be vaccinated?
Yes. Vaccination should be offered to individuals regardless of history of prior SARS-CoV-2 infection. CDC has summarized the available data on vaccine-induced immunity and disease-induced immunity here: www.cdc.gov/coronavirus/2019-ncov/science/science-briefs/vaccine-induced-immunity.html.
Viral testing to assess for current SARS-CoV-2 infection or serologic testing to assess for prior infection for the purposes of vaccine decision-making is not recommended. However, as with all vaccines, vaccination should be deferred until after recovery from moderate to severe illness. In addition, to minimize the risk of exposing others to SARS-CoV-2 virus, vaccination of a person diagnosed with COVID-19 generally should be deferred until criteria have been met for individuals with COVID-19 illness to discontinue isolation.
Although not required, people who recently had SARS-CoV-2 infection may consider delaying a primary series dose or the bivalent COVID-19 vaccine booster dose by 3 months from symptom onset or positive test (if infection was asymptomatic). According to CDC, increasing the time between infection and vaccination may result in an improved immune response to vaccination. Among vaccine recipients at increased risk of post-vaccination myocarditis (e.g., adolescent and adult males younger than age 40), an increased interval also may reduce the rare risk of myocarditis after vaccination. A recipient's individual risks for severe disease and current COVID-19 conditions in the community should be taken into account when deciding whether to delay vaccination up to 3 months after infection.
What is the difference between an "additional primary dose" of COVID-19 vaccine recommended for an immunocompromised person and a "booster dose"?
CDC defines an "additional primary dose" as a subsequent dose of vaccine administered to people who are less likely to develop a protective immune response after initial vaccination because of moderate or severe immunocompromise. All additional primary doses should be a monovalent COVID-19 vaccine, preferably the same brand as the previous primary series doses.
CDC defines a "booster dose" as a subsequent dose of vaccine administered to enhance or restore protection which might have declined over time after primary series vaccination.
How does CDC define being "up to date" on COVID-19 vaccination?
CDC has used the term "fully vaccinated" to refer to people who have completed a primary COVID-19 vaccine series. CDC uses the term "up to date" (UTD) to refer to a person who has received all doses recommended for their age and health status. As of September 1, 2022, all individuals age 12 years or older must have received a monovalent COVID-19 vaccine primary series plus a single bivalent mRNA COVID-19 vaccine booster dose to be considered up to date. Recommendations for children younger than age 12 years differ. The definition of up-to-date vaccination of each age group is available here: www.cdc.gov/vaccines/covid-19/downloads/COVID-19-vacc-schedule-at-a-glance-508.pdf.
Vaccine Products Back to top
What is an Emergency Use Authorization (EUA)?
Under section 564 of the Federal Food, Drug, and Cosmetic Act (FD&C Act), the FDA Commissioner may allow unapproved medical products or unapproved uses of approved medical products to be used in an emergency to diagnose, treat, or prevent serious or life-threatening diseases or conditions caused by chemical, biological, radiological or nuclear threat agents when there are no adequate, approved, and available alternatives. Vaccines that receive an EUA may later be fully licensed by the FDA.
Which vaccines are currently licensed by the FDA?
Pfizer-BioNTech COVID-19 Vaccine is licensed as a 2-dose primary series for individuals age 12 years and older. The brand name of this product is Comirnaty.
Moderna COVID-19 Vaccine is licensed as a 2-dose primary series for individuals age 18 years and older. The brand name of this product is Spikevax.
Recommended uses of these products outside the scope of the licensed 2-dose primary series are covered by an FDA emergency use authorization (EUA) or CDC emergency use instructions (EUI).
What are the differences in the purple cap (dilute before use), the two gray caps (do not dilute), the orange cap (dilute before use) and the maroon cap (dilute before use) formulations of Pfizer-BioNTech COVID-19 Vaccine?
There are different preparations of Pfizer-BioNTech COVID-19 vaccine that are distinguished by cap color and matching vial label trim. The maroon cap is the monovalent vaccine for recipients ages 6 months through 4 years and the orange cap is the monovalent vaccine for recipients 5 through 11 years. The purple cap is a monovalent formulation for recipients age 12 years or older that is no longer being produced: the last vials of purple cap expire at the end of September 2022.
Until the bivalent Pfizer-BioNTech vaccine for age 12 years and older was introduced in September 2022, a gray cap was used only on the monovalent COVID-19 vaccine that was authorized for recipients age 12 years or older. As of September 1, 2022, there are two different "gray cap" Pfizer-BioNTech products with different indications: read the labels carefully to avoid administering the wrong product.
Monovalent gray cap Pfizer-BioNTech vaccine is currently authorized only for use as a primary series vaccine in recipients age 12 years or older.
Bivalent gray cap Pfizer-BioNTech vaccine (stored and handled in the same way as the monovalent gray cap) includes mRNA encoding the spike protein of Omicron BA.4 and BA.5 subvariants and is recommended only for use as a single booster dose for people age 12 years and older who have completed, at minimum, a primary series of a monovalent COVID-19 vaccine.
The manufacturer has indicated that the reason for having two versions with a gray cap is that, with the exception of the addition of the mRNA for BA.4/BA.5 spike protein, the vaccine products are the same. However, because both products are in use and may be present in the same vaccine storage units, all users must be aware of the increased opportunity for medication errors and take all necessary steps to avoid administering the wrong product.
There is no Vaccine Information Statement (VIS) for recipients of COVID-19 vaccines. In place of the VIS, recipients should be given the FDA's EUA Fact Sheet for Recipients and Caregivers prepared for the specific formulation. All EUA Fact Sheets for licensed and authorized Pfizer-BioNTech formulations are posted by the FDA on this website: www.fda.gov/emergency-preparedness-and-response/coronavirus-disease-2019-covid-19/comirnaty-and-pfizer-biontech-covid-19-vaccine.
We don't have a VIS for COVID-19 vaccines. What information am I supposed to give patients in writing?
For each COVID-19 vaccine authorized under an Emergency Use Authorization (EUA), the Food and Drug Administration (FDA) requires that vaccine recipients or their caregivers are provided with certain vaccine-specific EUA information to help make an informed decision about vaccination. This is accomplished by providing an EUA Fact Sheet for Recipients and Caregivers. The Fact Sheet is similar in purpose and content to vaccine information statements (VISs) for licensed vaccines but differs in that the EUA Fact Sheet is specific to each authorized COVID-19 vaccine, is developed by the manufacturer of the vaccine, and is authorized by the FDA. There is a separate EUA Fact Sheet for Healthcare Providers for each formulation of a vaccine; however, some EUA fact sheets for recipients and caregivers may be designed for use with more than one product.
CDC has issued Emergency Use Instructions (EUI) for the use of the FDA-licensed formulations of Pfizer-BioNTech COVID-19 Vaccine (Comirnaty), or Moderna COVID-19 Vaccine (Spikevax) for certain people vaccinated with vaccines not authorized or approved by the FDA, whether given outside the United States or as part of a clinical trial. The EUI also addresses revaccination of people who have received hematopoietic cell transplant (HCT) or CAR-T-cell therapy. These instructions may differ from the FDA-approved labeling (the package insert). People vaccinated in accordance with these emergency use instructions should be given an EUI Fact Sheet at the time of vaccination. Information about CDC EUI and links to these fact sheets for providers and recipients or caregivers are available here: www.cdc.gov/vaccines/covid-19/eui/index.html.
Until there is a VIS for COVID-19 vaccine, FDA has issued revised fact sheets for Comirnaty and Spikevax that cover both their limited licensed indications as a primary series for people age 12 and older (Comirnaty) or age 18 and older (Spikevax) and their broader emergency use authorizations including the recommended bivalent booster doses (Pfizer-BioNTech, age 12 and older; Moderna, age 18 and older). Once a COVID-19 VIS is issued, the VIS and all available translations will be posted here: https://immunize.org/vis/.
Below are links to each Fact Sheet for Recipients and Caregivers by age group and product type:
1. Combined Pfizer-BioNTech COVID-19 Vaccine EUA fact sheet for recipients and caregivers about Comirnaty, the Pfizer-BioNTech COVID-19 Vaccine, and the Pfizer-BioNTech COVID-19 Vaccine, Bivalent (Original and Omicron BA.4/BA.5) (age 12 years and older, for use with purple cap and monovalent or bivalent gray cap products): www.fda.gov/media/153716/download
2. Pfizer-BioNTech COVID-19 Vaccine EUA fact sheet for recipients and caregivers (age 5 through 11 years, orange cap): www.fda.gov/media/153717/download
3. Pfizer-BioNTech COVID-19 Vaccine EUA fact sheet for recipients and caregivers (age 6 months through 4 years, maroon cap): www.fda.gov/media/159313/download
4. Combined fact sheet for recipients and caregivers about Spikevax and Moderna COVID-19 Vaccine (age 12 years and older), and the Moderna COVID-19 Vaccine, Bivalent (Original and Omicron BA.4/BA.5), age 18 years and older: www.fda.gov/media/144638/download
5. Moderna COVID-19 fact sheet for recipients and caregivers (age 6 years through 11 years): www.fda.gov/media/159310/download
6. Moderna COVID-19 fact sheet for recipients and caregivers (age 6 months through 5 years, blue cap, magenta [hot pink] vial label border): www.fda.gov/media/159309/download
7. Janssen COVID-19 Vaccine EUA fact sheet for recipients and caregivers (age 18 years and older): www.fda.gov/media/146305/download
8. Novavax COVID-19 Vaccine, Adjuvanted EUA Fact Sheet for recipients and caregivers (age 18 years and older): www.fda.gov/media/159898/download
What are the differences among the presentations of Moderna COVID-19 Vaccine?
Moderna COVID-19 Vaccine has 3 monovalent primary series presentations for different age groups or uses, plus one bivalent booster dose product for age 18 years and older, each with a different vial cap and label combination:
Blue vial cap and magenta (hot pink) bordered label (monovalent) contains 10 doses (25 mcg per 0.25 mL dose) for primary series doses in children age 6 months through 5 years.
Blue vial cap and purple-bordered label (monovalent) contains 5 doses (50 mcg per 0.5 mL dose): it is for primary series doses in children age 6 through 11 years. The vial label indicates it is for booster doses in adults; however, the FDA emergency use authorization of the use of this product as a booster dose for adults has been revoked and it should not be used as a booster dose. Only bivalent vaccine is authorized and recommended as a booster dose in adults.
Red vial cap and blue-bordered label contains 10 doses (100 mcg per 0.5 mL dose) for use only as primary series doses in adults age 18 years or older
Blue vial cap and gray-bordered label (bivalent): each dose contains 25 mcg of original strain spike protein mRNA and 25 mcg BA.4/BA.5 Omicron subvariant spike protein mRNA, for use only as a single booster dose in adults age 18 years or older
Vaccinators who stock multiple presentations should check three times to confirm that they are administering the proper product with the proper dose and dose volume for each patient.
 
What are mRNA vaccines?
Both the Pfizer-BioNTech COVID-19 Vaccine and the Moderna COVID-19 (mRNA-1273) Vaccine are lipid nanoparticle-formulated, nucleoside-modified mRNA vaccines encoding the prefusion spike glycoprotein of SARS-CoV-2, the virus that causes coronavirus disease 2019. The fall 2022 bivalent mRNA vaccine formulations target the original SARS-CoV-2 spike protein and the Omicron BA.4/BA.5 spike protein. Both mRNA vaccine brands have been associated with a rare occurrence of myocarditis and/or pericarditis; cases have occurred predominantly among males ages 12 through 39. Visit this CDC website for more details about how mRNA vaccines work: www.cdc.gov/coronavirus/2019-ncov/vaccines/different-vaccines/mrna.html.
How well did the mRNA COVID-19 vaccines work in the clinical trials?
The FDA EUA was issued based upon the short-term effectiveness of these vaccines at preventing symptomatic illness with COVID-19. The Pfizer-BioNTech vaccine (Comirnaty) was licensed by FDA with a reported vaccine efficacy of 91.1% against symptomatic disease among recipients age 16 years or older up to 6 months after dose 2. Both Moderna and Pfizer-BioNTech vaccines maintain approximately 90% protection against severe disease for at least 6 months after vaccination. Early observational studies of short-term effectiveness in a variety of populations were consistent with the clinical trial results. Vaccine effectiveness wanes over time and can be improved by the administration of booster doses as recommended by CDC. Vaccine effectiveness may be different for new variants of COVID-19. The bivalent mRNA vaccines introduced in September 2022 target the original SARS-CoV-2 spike protein as well as the Omicron BA.4/BA.5 spike protein; they have been proven to stimulate higher levels of antibodies against the BA.4 and BA.5 Omicron subvariants of SARS-CoV-2 virus when compared to the original monovalent vaccine, however, no vaccine effectiveness data were available at the time of the ACIP recommendation for their use.
What is the difference between the original mRNA vaccines and the new "bivalent" mRNA vaccine first recommended as a booster dose in September 2022?
The original mRNA vaccines manufactured by Pfizer-BioNTech and Moderna contain only mRNA encoding for the spike protein of the original SARS-CoV-2 virus, meaning they were "monovalent." The bivalent vaccines in the United States are made exactly like the original monovalent vaccines, except that half the mRNA in the vaccine encodes for the original strain and half encodes for the spike protein found on the Omicron BA.4/BA.5 subvariants circulating in the summer of 2022. The addition of the updated mRNA is intended to boost the production of antibodies that protect more effectively against disease caused by subvariants circulating currently and in the near future.
The process of updating the strain without changing anything else is similar to the seasonal strain changes made for influenza vaccinations each year; FDA does not require manufacturers to repeat the large-scale clinical trials necessary for the original products before authorizing the updated vaccines. Vaccine safety, side effects, and risk of allergic reactions are expected to be unchanged in the bivalent vaccines compared to the monovalent vaccines of the same brand and dose.
Please describe the Janssen COVID-19 Vaccine (Johnson & Johnson).
The Janssen vaccine is a recombinant, replication-incompetent (unable to reproduce) adenovirus serotype 26 (Ad26) vector vaccine, encoding the stabilized prefusion spike glycoprotein of SARS-CoV-2. On February 27, 2021, the FDA first issued an Emergency Use Authorization (EUA) for the Janssen COVID-19 (Ad.26.COV2.S) Vaccine (Johnson & Johnson). Due to the extremely rare risk of the serious complications of thrombosis with thrombocytopenia syndrome (TTS) or Guillain-Barre syndrome (GBS) following vaccination with this product, the Janssen COVID-19 Vaccine is currently authorized for use in individuals 18 years of age and older for whom other FDA-authorized or approved COVID-19 vaccines are not accessible or clinically appropriate, and for individuals 18 years of age and older who elect to receive the Janssen COVID-19 Vaccine because they would otherwise not receive a COVID-19 vaccine.
Primary vaccination of people who are not moderately or severely immunocompromised consists of a single dose of Janssen vaccine administered intramuscularly. A booster dose of a bivalent mRNA COVID-19 vaccine is recommended for these recipients at least 2 months (8 weeks) following the primary dose or any more recent monovalent booster dose administered to a person who received Janssen vaccination.
People age 18 years or older with moderate to severe immunocompromise who receive a primary dose of Janssen vaccine should receive an additional dose of a monovalent mRNA vaccine at least 28 days after the Janssen vaccine. A booster dose of a bivalent mRNA vaccine is recommended at least 2 months after the additional primary dose.
How well did the Janssen COVID-19 Vaccine work in the clinical trials?
A large phase 3 trial was initiated in September 2020 and enrolled more than 43,000 individuals in multiple countries, including the United States, Brazil, and South Africa. Interim results demonstrated a 66% reduction in the risk of symptomatic COVID-19 beginning at least 14 days following vaccination; efficacy against severe disease was higher. The risk of hospitalization 14 days or more after vaccination was reduced by 93% compared to placebo recipients; no hospitalizations occurred among vaccine recipients 28 days or more after vaccination. No deaths related to COVID-19 infection occurred among vaccine recipients, while seven occurred among placebo recipients.
In the months following EUA, vaccine effectiveness against severe disease and hospitalization remained high against known variants, including the Delta variant, even as protection against milder illness appeared reduced. Receipt of a booster dose at least 2 months after the primary dose substantially increases neutralizing antibodies to levels consistent with a high degree of protection against symptomatic infection. Due to the occurrence of very rare but serious side effects, mRNA vaccines or Novavax protein subunit vaccine (which are not associated with these side effects) are preferred over Janssen vaccine for primary vaccination of eligible recipients in the United States. Vaccine effectiveness may be different for different variants of COVID-19.
What is the Novavax COVID-19 Vaccine?
Novavax COVID-19 Vaccine, Adjuvanted contains the original SARS-CoV-2 spike protein and Matrix-M adjuvant. The saponin-based adjuvant is made from extracts of the bark of the Soapbark tree native to Chile. It is added to enhance the immune response of the vaccine recipient. The spike protein is produced in insect cells. It was authorized in July 2022 for emergency use in adults age 18 years or older as a two-dose primary series, with the doses given at least 3 weeks apart. It is a monovalent vaccine and is not authorized for use as a booster dose.
The initial ACIP recommendations for use of Novavax COVID-19 Vaccine are available here: www.cdc.gov/mmwr/volumes/71/wr/mm7131a2.htm?s_cid=mm7131a2_w.
How well does the Novavax COVID-19 Vaccine work?
The effectiveness of Novavax COVID-19 Vaccine against currently circulating variants of SARS-CoV-2 is not precisely known. Clinical trials of this vaccine were conducted against earlier variants no longer in circulation; however, the vaccine showed very good effectiveness against moderate to severe disease during clinical trials. Testing conducted on antibodies in the serum of Novavax vaccine recipients suggests that vaccination provides substantial protection against severe disease and death caused by currently circulating variants, consistent with other available COVID-19 vaccines.
Where can I obtain detailed information about the COVID-19 vaccines?
CDC has developed a "one-stop" product-specific webpage for each COVID-19 vaccine with all of the important details that immunization providers need to know.
Pfizer-BioNTech COVID-19 Vaccine (all formulations): www.cdc.gov/vaccines/covid-19/info-by-product/pfizer/index.html
Moderna COVID-19 Vaccine: www.cdc.gov/vaccines/covid-19/info-by-product/moderna/index.html
Janssen COVID-19 Vaccine: www.cdc.gov/vaccines/covid-19/info-by-product/janssen/index.html
Novavax COVID-19 Vaccine: www.cdc.gov/vaccines/covid-19/info-by-product/novavax/index.html
In addition to CDC, each company has a detailed EUA Fact Sheet for healthcare providers administering vaccine.
1. Pfizer-BioNTech COVID-19 Vaccine (monovalent, primary series for age 12 years and older, purple cap): www.fda.gov/media/153713/download
2. Pfizer-BioNTech COVID-19 Vaccine (monovalent, primary series for age 12 years and older, gray cap): www.fda.gov/media/153715/download
3. Pfizer-BioNTech COVID-19 Vaccine, Bivalent (Original and Omicron BA.4/BA.5) booster dose for age 12 years and older, gray cap): www.fda.gov/media/161327/download
4. Pfizer-BioNTech COVID-19 Vaccine (monovalent, primary or booster dose for age 5 through 11 years, orange cap): www.fda.gov/media/153714/download
5. Pfizer-BioNTech COVID-19 Vaccine (monovalent, primary series for age 6 months through 4 years, maroon cap): www.fda.gov/media/159312/download
6. Moderna COVID-19 Vaccine (monovalent, primary series age 12 years and older, red cap, light blue label border): www.fda.gov/media/157233/download
7. Moderna COVID-19 Vaccine, Bivalent (Original and Omicron BA.4/BA.5) (booster dose for age 18 years and older, dark blue cap, gray label border): www.fda.gov/media/161318/download
8. Moderna COVID-19 Vaccine (monovalent, primary series dose for age 6 years through 11 years, dark blue cap, purple label border): www.fda.gov/media/159308/download
9. Moderna COVID-19 Vaccine (monovalent, primary series dose age 6 months through 5 years blue cap, magenta [hot pink] label border): www.fda.gov/media/159307/download
10. Novavax COVID-19 Vaccine (primary series, age 18 years and older): www.fda.gov/media/159897/download
11. Janssen COVID-19 Vaccine (primary series, age 18 years and older): www.fda.gov/media/146304/download
COVID-19 Vaccines for Children under 12 Years Back to top
What are the recommendations for COVID-19 vaccination of children younger than 12 years?
All children age 6 months and older should be vaccinated against COVID-19. Both monovalent (original) mRNA vaccines (Pfizer-BioNTech and Moderna) are authorized for use in children down to 6 months of age. The number of doses and recommended formulations vary by age and by immunocompromised health status. Children younger than age 12 years are not authorized or recommended to receive the bivalent COVID-19 vaccine booster dose recommended for people age 12 years and older.
Refer to the CDC's current recommended immunization schedule for age groups beginning at 6 months in this PDF document: www.cdc.gov/vaccines/covid-19/downloads/COVID-19-immunization-schedule-ages-6months-older.pdf.
Our clinic does not stock the orange cap formulation of Pfizer-BioNTech COVID-19 Vaccine for children age 5 through 11 years. Could we draw up a 10 microgram (mcg) dose out of the monovalent adolescent/adult formulation to vaccinate these children?
No. Children 5 through 11 years should only be vaccinated with a 10-mcg dose (0.2 mL) of the orange cap (dilute before use) Pfizer-BioNTech formulation specifically authorized for ages 5 through 11 years, except as permitted by the FDA when a child is within 21 days of their 12th birthday, as described in the next question.
A dose of the purple cap (dilute before use) or gray cap (do not dilute) monovalent formulation for adolescents and adults delivers 30 mcg in a 0.3 mL volume. Ten mcg (the dose for a child 5 through 11 years) would be just 0.1 mL, a volume too small to reliably deliver the correct amount intramuscularly. It is never acceptable to alter the dilution volume or to dilute a formulation that should not be diluted in order to create a larger dose volume.
My patient turns 12 years old later this month. Should they get the lower-dose Moderna or Pfizer-BioNTech primary series vaccine formulation approved for age 11 years now or wait and get the higher dose primary series products authorized at age 12?
Do not wait. The simple rule is that children should receive a vaccine dosage and formulation authorized specifically for their age on the day of vaccination with each dose. However, the FDA authorization provides flexibility for product selection when managing children who transition from a younger to an older age group during the primary series. CDC has prepared reference documents outlining recommended and acceptable options for each mRNA vaccine when children transition from a younger to an older age group while receiving the primary series.
Moderna: www.cdc.gov/vaccines/covid-19/downloads/Moderna-Child-Age-Transition-508.pdf
Pfizer-BioNTech: www.cdc.gov/vaccines/covid-19/downloads/Pfizer-Child-Age-Transition-508.pdf
What do we know about the orange cap monovalent Pfizer-BioNTech COVID-19 Vaccine effectiveness and side effects in children age 5 through 11 years?
Preliminary clinical trial results (initial enrollment of 2,268 children) showed that two 10-microgram (mcg) doses of orange cap (dilute before use) Pfizer-BioNTech COVID-19 Vaccine formulation for age 5 through 11 years, administered 21 days apart, reduced the risk of symptomatic COVID-19 illness by 90.9 percent for at least two months. The immune response to this dose in this age group was at least as strong as the immune response to two 30 mcg doses of the purple cap Pfizer-BioNTech COVID-19 Vaccine formulation among recipients age 16 through 25 years.
During the 7 days following vaccination, almost 9 in 10 children reported a local reaction, primarily pain at the injection site, and 2 of 3 reported a systemic reaction (most commonly fatigue or headache). The vast majority of reactions were mild or moderate and resolved within 12 days; reactions were milder than those reported by young adult recipients of the purple cap formulation. Systemic reactions were more likely to be reported following dose 2. No serious adverse events related to vaccination were observed in the clinical trial.
What do we know about the safety and effectiveness of Moderna and Pfizer-BioNTech mRNA COVID-19 vaccines in the youngest children?
Variants in circulation at the time of the clinical trials in young children (6 months through 4 years for Pfizer-BioNTech and 6 months through 5 years for Moderna) are no longer in circulation, so it is not possible to state with certainty how effective these vaccines are in young children against currently circulating variants. However, the recommended schedules of both Moderna and Pfizer-BioNTech vaccines in children as young as 6 months produce an immune response consistent with the immune response seen in older age groups where effectiveness against symptomatic infection, and particularly effectiveness against severe COVID-19, has been demonstrated.
Both vaccines have been demonstrated to be safe, with side effects typical of those in older age groups. The most common local reaction in this age group is pain at the injection site; the most common systemic symptom in older children was fatigue and in younger children (6 through 23 months) irritability/crying and sleepiness were most common. Fever may occur after either vaccination. Febrile seizures can occur in infants and young children ages 6 months through 5 years as a result of any condition that causes a fever (most common with high fevers). Febrile seizures are uncommon after vaccination. Febrile seizures were rare after mRNA COVID-19 vaccine clinical trials in this age group, but CDC is monitoring for this adverse event following vaccination in infants and young children.
No cases of myocarditis were reported during the clinical trials for either vaccine; however, the clinical trials were not large enough to detect a very small risk, and CDC is monitoring for this adverse event among recipients. Lengthening the interval between doses 1 and 2 may substantially reduce the rare risk of myocarditis. CDC recommends that the interval between dose 1 and 2 may be up to 8 weeks for all children and adults through age 64, unless rapid protection is a priority because the recipient has either a high risk of severe disease or a high risk of exposure.
COVID-19 Vaccines for Adolescents and Adults Back to top
What COVID-19 vaccine options are available for adolescents and adults ages 12 years and older?
The purple cap (last doses expire September 2022) and gray cap (do not dilute) monovalent mRNA formulations of the Pfizer-BioNTech COVID-19 Vaccine are licensed (with the brand name Comirnaty) as a primary series for age 12 years and older.
The gray cap Pfizer-BioNTech COVID-19 Vaccine, Bivalent (Original and Omicron BA.4/BA.5) is authorized for emergency use as a booster dose for recipients age 12 years and older.
Moderna (Spikevax) monovalent mRNA vaccine is licensed for the primary series in ages 18 years and older and is authorized for emergency use as a primary series in people age 12 through 17 years.
Moderna COVID-19 Vaccine, Bivalent (Original and Omicron BA.4/BA.5) is authorized for emergency use as a booster dose for recipients age 18 years and older.
Novavax COVID-19 Vaccine (protein subunit, adjuvanted) is authorized for emergency use as a primary series in adults age 18 years and older.
Janssen COVID-19 Vaccine (adenoviral vector vaccine) is authorized for emergency use in certain people age 18 years and older for whom vaccination with an alternative vaccine is not feasible.
Why has CDC provided the option to increase the primary series interval between dose 1 and dose 2 of mRNA and Novavax COVID-19 vaccines up to 8 weeks?
CDC recommends the option of an 8-week interval between doses 1 and 2 of mRNA and Novavax vaccines for most people. Large observational studies in other countries have provided evidence that an 8-week interval may result in higher antibody levels and a reduced risk of vaccine-associated myocarditis, which is most likely to occur after dose 2. For this reason, an 8-week interval of an age-appropriate product may be optimal for some people age 6 months through 64 years, especially males ages 12 through 39 years who are at the greatest risk of myocarditis after dose 2.
Shorter intervals (3 weeks for Pfizer-BioNTech and Novavax; 4 weeks for Moderna) protect the recipient more quickly. Therefore, a shorter interval remains the recommended interval for the following groups:
All people who are moderately to severely immunocompromised
All adults age 65 years and older
Others who need rapid protection due to increased risk of exposure or risk of severe disease
What do we know about the monovalent Pfizer-BioNTech COVID-19 Vaccine effectiveness and side effects in children and young teens in the 12- to 15-year-old age group?
Clinical trial results demonstrated that the immune response of young adolescents in this age group to two 30 mcg doses separated by 21 days was similar to that observed in people age 1625 years. No symptomatic cases of COVID-19 were detected among fully vaccinated people age 1215 years. Among vaccine recipients age 1215 years, side effects during the 7 days after vaccination were commonly reported (90.9% of vaccine recipients reported a local reaction and 90.7% reported a systemic reaction). Most reactions were mild to moderate. Pain at the injection site was the most common local reaction. One in 10 reported a side effect that interfered with daily activities. Side effects usually resolved after 12 days. Systemic side effects (e.g., fever, fatigue, headache, muscle pain) were more commonly reported after the second dose than after the first dose. No specific safety concerns were identified among adolescent vaccine recipients.
The safety and side effects of the bivalent mRNA vaccine introduced in September 2022 is expected to be consistent with the monovalent product.
Special Populations Back to top
Are COVID-19 vaccines safe during pregnancy?
A growing body of evidence on COVID-19 vaccination during pregnancy has not indicated any safety or effectiveness concerns for vaccination at any stage of pregnancy; the benefits of vaccination clearly outweigh any known or potential risks of COVID-19 vaccination during pregnancy. The currently authorized or licensed COVID-19 vaccines are non-replicating vaccines and cannot cause infection in either the mother or the fetus. No evidence exists of risk to the fetus from vaccinating pregnant people with non-replicating vaccines in general. Just like the general population, COVID-19 vaccines other than Janssen are preferred during pregnancy; Janssen vaccine may be considered when mRNA or Novavax vaccination is not feasible.
No safety concerns were found in animal developmental and reproductive toxicity studies of animals that received Pfizer-BioNTech, Moderna, Novavax, or Janssen vaccines. Reassuring early safety data on mRNA COVID-19 vaccines administered to people during pregnancy have been published by CDC. Data from the Vaccine Adverse Events Reporting System (VAERS), the v-safe surveillance system, and the v-safe pregnancy registry have not signaled any safety concerns for pregnant people who were vaccinated or their infants. The vaccine manufacturers are following the pregnancy outcomes of people in the clinical trials who became pregnant. Additional studies in pregnant people are ongoing in order to fully evaluate pregnancy and birth outcomes.
Pregnant individuals should be vaccinated and are encouraged to enroll in CDC's voluntary COVID-19 vaccine safety surveillance system, v-safe. The v-safe pregnancy registry follows outcomes among pregnant people who are vaccinated.
The safety of bivalent mRNA vaccines is expected to be no different from monovalent mRNA vaccines; all people who are pregnant are recommended to receive a single bivalent mRNA booster dose at least 2 months after completing their primary series or receiving their most recent monovalent booster dose.
Can COVID-19 vaccination lead to fertility problems?
There is currently no evidence that any of the COVID-19 vaccines affect current or future fertility. In fact, there is currently no evidence that any vaccines cause fertility problems. Many individuals have become pregnant after receiving COVID-19 vaccine; ongoing long-term studies of pregnancy outcomes following vaccination are underway.
Are COVID-19 vaccines recommended during pregnancy?
Yes. COVID-19 vaccination is recommended for all people who are pregnant, lactating, trying to get pregnant now, or planning for future pregnancy. Pregnant people are at increased risk of severe complications and death from COVID-19 compared to non-pregnant people of the same age. Those who contract COVID-19 during pregnancy also have almost twice the risk of stillbirth compared to those who do not contract COVID-19 during pregnancy. Recent studies have shown that antibodies produced after COVID-19 vaccination during pregnancy are transferred to the newborn, and COVID-19 vaccination of people who are pregnant reduces the risk of COVID-19 hospitalization in infants younger than 6 months. Pregnant people should receive a bivalent mRNA booster dose during pregnancy, if eligible.
CDC, the American College of Obstetricians and Gynecologists (ACOG), and the Society for Maternal-Fetal Medicine (SMFM) all recommend vaccination of pregnant people at any stage of pregnancy.
For more details about COVID-19 vaccination during pregnancy, visit CDC's webpage, "COVID-19 Vaccines while Pregnant or Breastfeeding": www.cdc.gov/coronavirus/2019-ncov/vaccines/recommendations/pregnancy.html.
Are COVID-19 vaccines recommended if the recipient is breastfeeding?
Yes. COVID-19 vaccination is recommended for people who are lactating.
There are limited data on the safety of currently available COVID-19 vaccines on the breastfed infant or milk production/excretion. However, the currently available COVID-19 vaccines cannot cause infection in either the lactating person or the infant. More data are needed to determine if COVID-19 antibodies present in breastmilk convey protection against SARS-CoV-2 infection for infants.
What is the COVID-19 vaccination schedule for moderately or severely immunocompromised people?
The schedule of COVID-19 vaccination was simplified for all people age 12 years and older in September 2022 with the authorization and recommendation of a single booster dose of bivalent mRNA vaccine administered at least 2 months after completion of a primary series or administration of the most recent monovalent booster dose.
Most people with moderate or severe immunocompromise are recommended to receive an additional monovalent primary series dose after the routine primary series. The exceptions are adults who receive a Novavax COVID-19 Vaccine primary series and children age 6 months through 4 years who receive the standard Pfizer-BioNTech 3-dose primary series. Please review the CDC "At -A-Glance" COVID-19 Vaccination Schedules (pdf) for the current recommended vaccination schedules for each vaccine for immunocompetent and immunocompromised people in each eligible age group: www.cdc.gov/vaccines/covid-19/downloads/COVID-19-vacc-schedule-at-a-glance-508.pdf.
Immunocompromised people who receive an additional primary dose should be counseled that they may still have a reduced immune response to COVID-19 vaccination. They should be advised to continue other recommended infection prevention measures, such as wearing a face mask and avoiding crowds, to limit their risk of exposure to the SARS-CoV-2 virus. Healthcare providers should consult current guidelines for the use of Evusheld (tixagevimab and cilgavimab, AstraZeneca) administered every 6 months for pre-exposure prophylaxis of moderately or severely immunocompromised adults, in addition to vaccination.
Exactly which moderately or severely immunocompromised groups are recommended to receive an additional primary dose or booster of mRNA vaccine?
The age groups of immunocompromised people eligible for an additional primary series dose are all age 6 months or older who receive a Moderna primary series, all age 5 years and older who receive a Pfizer-BioNTech primary series, and all 18 or older who receive a Janssen primary dose (monovalent mRNA vaccine should be used as the additional primary series dose for a Janssen vaccine recipient). An additional primary series dose is not recommended for Pfizer-BioNTech recipients younger than age 5 years because all children in that age group receive a 3-dose primary series. An additional primary series dose also is not recommended for adults who receive a 2-dose primary series of Novavax vaccine at this time.
All people age 5 years and older are recommended to receive a booster dose following completion of the primary series. Those age 12 years and older should receive a single bivalent mRNA vaccine booster dose at least 2 months after completion of the monovalent primary series or after their most recent monovalent booster dose. See the CDC At-A-Glance COVID-19 Vaccination Schedules for details: www.cdc.gov/vaccines/covid-19/downloads/COVID-19-vacc-schedule-at-a-glance-508.pdf.
The conditions and treatments that may result in moderate or severe immunocompromise in these eligible age groups include but are not limited to:
Active treatment for solid tumor and hematologic malignancies
Receipt of solid-organ transplant and taking immunosuppressive therapy
Receipt of CAR-T-cell or hematopoietic stem cell transplant (within 2 years of transplantation or taking immunosuppression therapy)
Moderate or severe primary immunodeficiency (such as DiGeorge syndrome or Wiskott-Aldrich syndrome)
Advanced or untreated HIV infection
Active treatment with high-dose corticosteroids (in other words, 20 mg or more of prednisone or equivalent per day), alkylating agents, antimetabolites, transplant-related immunosuppressive drugs, cancer chemotherapeutic agents classified as severely immunosuppressive, tumor-necrosis factor (TNF) blockers, and other biologic agents that are immunosuppressive or immunomodulatory
Additional factors to consider in assessing the general level of immune competence in a patient include disease severity, duration, clinical stability, complications, comorbidities, and any potentially immune-suppressing treatment. A patient's clinical care team is in the best position to evaluate the degree of immunocompromise and timing of vaccination.
For additional information, see CDC's interim clinical considerations for this population: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us.html#immunocompromised.
I have an oncology patient who was up to date on COVID-19 vaccination but is now in need of hematopoietic cell transplant (HCT). Will she require revaccination after HCT?
Yes. According to CDC's interim clinical considerations for COVID-19 vaccination (www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us.html#immunocompromised), you should revaccinate against COVID-19 with Moderna, Novavax, or Pfizer-BioNTech COVID-19 vaccine, regardless of vaccine administered originally. Recipients of HCT or CAR-T-cell therapy should undergo revaccination for the monovalent primary series and bivalent booster doses received prior to or during treatment. Do not repeat any monovalent booster doses: only monovalent primary series doses should be repeated and, if the patient is age 12 years or older, once the primary series has been completed, administer one bivalent mRNA booster dose at the appropriate interval. Revaccination should start at least 3 months (12 weeks) after transplant or CAR-T-cell therapy.
Revaccination, as above, may also be considered for patients who received 1 or more doses of COVID-19 vaccine (primary series and bivalent booster doses) during treatment with B-cell-depleting therapies (e.g., rituximab, ocrelizumab) that were administered over a limited period of time. The suggested interval to start revaccination is about 6 months after completion of the B-cell-depleting therapy. Timing of vaccination for patients who receive B-cell-depleting therapies on an ongoing basis is addressed separately by CDC at the considerations link in the paragraph above.
CDC's guidance states that the individual patient's clinical team is best positioned to determine the degree of immune compromise, need for revaccination, and appropriate timing of revaccination.
CDC Emergency Use Instructions (EUI) for each mRNA vaccine product provide additional details on revaccination of patients in these circumstances. They are accessible on CDC's EUI main page: www.cdc.gov/vaccines/covid-19/eui/index.html.
My patient receives periodic infusions of rituximab for immunosuppressive treatment of an immune system disorder. Should we try to coordinate the timing of his COVID-19 vaccinations around his infusion schedule?
According to CDC's interim clinical considerations for the use of COVID-19 vaccines, whenever possible, COVID-19 vaccines should be administered at least 2 weeks before initiation or resumption of immunosuppressive therapies. For patients who receive B-cell-depleting therapies on a continuing basis, COVID-19 vaccines should be administered approximately 4 weeks before the next scheduled therapy.
CDC also notes that timing of COVID-19 vaccination should take into consideration current or planned immunosuppressive therapies, optimization of both the patient's medical condition and response to vaccination, and individual benefits and risks. Review the CDC interim clinical considerations for vaccination of people with moderate or severe immunocompromise: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us.html#immunocompromised.
Should I conduct serologic testing or cellular immune testing before or after offering an additional primary dose of mRNA vaccine to an immunocompromised patient?
No. Serologic testing or cellular immune testing before or after an additional primary dose (outside the context of research studies) is not recommended.
Does it matter which brand of mRNA vaccine I give to an immunocompromised person who is recommended to receive an additional primary dose?
CDC recommends that the additional monovalent primary dose be given at least 28 days after dose 2 of an mRNA vaccine or after the single primary dose of Janssen vaccine. If mRNA vaccine is used for the primary series, the 3rd dose should be the same monovalent brand as the first two doses of the primary series. However, if the same brand is unavailable, you may administer the other brand of monovalent mRNA vaccine. If using Moderna, a full monovalent primary series dose should be administered as the additional primary dose. Either monovalent mRNA vaccine may be used as the additional primary dose for a recipient of a primary dose of Janssen vaccine. The bivalent mRNA booster doses are not authorized for use as the additional primary series dose.
Novavax vaccine is authorized only for use as a 2-dose primary series vaccine and is not intended to be used in a mixed primary series schedule with mRNA or Janssen vaccines. At this time, no additional primary series dose is recommended for immunocompromised adults who receive a 2-dose Novavax vaccine primary series.
Note that immunocompromised children age 6 months through 4 years who receive a standard 3-dose primary series of Pfizer-BioNTech vaccine are not recommended to receive an additional (fourth) primary series dose.
My patient takes high dose steroids and received a single dose of Janssen COVID-19 Vaccine (Johnson & Johnson) in late March 2021. He fits the definition for moderate or severe immunocompromise. Should I give him an additional primary dose of Janssen vaccine?
All recipients of a primary dose of Janssen vaccine should receive an additional primary dose of either monovalent mRNA vaccine at least 28 days later.
For all vaccination schedule options, including the schedule for an immunocompromised person who received a primary Janssen vaccine dose, refer to the At-A-Glance COVID-19 Vaccination Schedules document from CDC: www.cdc.gov/vaccines/covid-19/downloads/COVID-19-vacc-schedule-at-a-glance-508.pdf.
My patient, age 45, is immunocompromised and is recommended to receive an additional primary dose of mRNA COVID-19 vaccine, but it has already been more than 6 months since his second mRNA dose. What do I do now?
The patient should receive his third monovalent primary dose now, using the same monovalent brand as the first two doses, if feasible. If the primary series is Moderna, a full 100 mcg additional primary dose should be used. Advise the patient to return at least 2 months after receiving the additional primary monovalent vaccine dose to receive a single bivalent mRNA booster dose.
For all recommended COVID-19 vaccination schedule options, see the At-A-Glance COVID-19 Vaccination Schedules document from CDC: www.cdc.gov/vaccines/covid-19/downloads/COVID-19-vacc-schedule-at-a-glance-508.pdf.
My patient is medically complex and severely immunocompromised and our clinical team has concerns that the recommended schedule of COVID-19 vaccination for immunocompromised patients may not be adequate. Does CDC permit any latitude in the COVID-19 vaccination schedule for such patients?
On a case-by-case basis, providers caring for moderately or severely immunocompromised patients may administer mRNA COVID-19 vaccines outside of the FDA and CDC dosing intervals based on clinical judgment when the benefits of vaccination are deemed to outweigh the potential and unknown risks for the recipient. However, CDC cautions that providers should not routinely administer doses of COVID-19 vaccine beyond those recommended. See CDC's statement here: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us.html#additional-considerations.
Administering Vaccines Back to top
How are COVID-19 vaccines administered?
All COVID-19 vaccines are administered intramuscularly. Preparation details and dose volume vary by product.
Has CDC provided clinical guidance on what to do if an error occurs while administering COVID-19 vaccinations?
Yes. CDC has published an appendix to its interim clinical considerations for the use of COVID-19 vaccines to address a wide range of errors in vaccine administration. It includes a detailed table outlining actions to take after an error has occurred: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us-appendix.html#appendix-d.
Errors addressed include the following:
Incorrect route or site
Incorrect use of bivalent booster dose as a primary series dose
Incorrect use of a monovalent primary series dose as a booster dose
Incorrect age (including administration of a formulation or brand of vaccine to a person in an age group not authorized or approved for that vaccine)
Incorrect dosing interval
Incorrect dose (high or low)
Administration after improper storage conditions
Administration after the expiration/beyond use date
Diluent errors (wrong diluent, too much or too little) with the Pfizer-BioNTech vaccines
Ask the Experts refers our readers to these CDC resources for the most current and comprehensive guidance on COVID-19 vaccine administration errors and how to manage them.
A dose of COVID-19 vaccine was administered subcutaneously instead of by the intramuscular route. Does the dose need to be repeated?
No. CDC does not recommend repeating the dose of any COVID-19 vaccine in circumstances where the dose is administered in an incorrect route or an incorrect site (i.e., not in the deltoid or anterolateral thigh).
During vaccination, the needle came loose and vaccine leaked out around it. Do we need to repeat the dose?
It depends on how much of the dose was successfully administered. If, in your judgment, the patient received at least half of the vaccine dose, do not repeat the dose. However, if you judge that less than half the dose was administered, revaccinate the recipient immediately (no minimum interval) with a full dose in the opposite arm.
A patient in clinic inadvertently received a monovalent Moderna COVID-19 dose as a booster instead of the recommended bivalent booster dose. What do we do?
CDC experts advise that, in general, you do not need to repeat the dose. However, you may administer 1 bivalent booster dose as a repeat dose based on clinical judgement and patient preference. In this case, space the repeat dose after the dose given in error by at least 2 months.
A report to the federal Vaccine Adverse Event Reporting System (VAERS) should be filed to document the error: https://vaers.hhs.gov. Always check the vial label at least 3 times to confirm you are administering the correct dose to the correct patient. The correct Pfizer-BioNTech and Moderna booster vaccine labels state that they are bivalent (Original and Omicron BA.4/BA.5).
See detailed guidance on COVID-19 vaccination errors at: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us-appendix.html#appendix-d.
An immunocompromised patient, age 30, should have received an additional (3rd) primary series dose of monovalent mRNA Moderna COVID-19 Vaccine, but was given the bivalent mRNA Moderna COVID-19 Vaccine booster dose in error. What do we do?
When the bivalent mRNA vaccine is inadvertently administered instead of a primary series dose, CDC's recommendations differ, depending on which brand was used.
CDC recommends that the dose should not be repeated if bivalent Pfizer-BioNTech vaccine was administered.
When bivalent Moderna vaccine is inadvertently given as a primary series dose, CDC recommends repeating the dose immediately with the 100-mcg monovalent Moderna primary series dose, because the bivalent Moderna vaccine dose (50 mcg) is a lower-than-authorized dose for the primary series.
When considering repeating the Moderna vaccine dose, CDC further explains that some experts suggest delaying the repeat dose for 8 weeks after the invalid dose based on the rare risk of myocarditis and pericarditis from mRNA and Novavax COVID-19 vaccines, particularly in groups at increased risk for myocarditis and pericarditis (e.g., males ages 1239 years). Individual risk for COVID-19 and the likelihood for an adverse event following vaccination should be taken into consideration when recommending a longer interval.
A report to the federal Vaccine Adverse Event Reporting System (VAERS) should be filed to document the error: https://vaers.hhs.gov. Always check the vial label at least 3 times to confirm you are administering the correct dose to the correct patient. The correct Pfizer-BioNTech and Moderna booster vaccine labels state that they are bivalent (Original and Omicron BA.4/BA.5).
See CDC guidance on COVID-19 vaccination errors here: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us-appendix.html#appendix-d.
Scheduling Vaccines Back to top
Where can I find the latest information on schedules of COVID-19 vaccines?
The recommended schedules for COVID-19 vaccines vary by brand, age group, and by the presence of moderate or severe immunocompromise. Schedules for people age 12 years and older were simplified on September 1, 2022, with the recommendation for all people age 12 years and older to receive a single bivalent mRNA booster dose at least 2 months following completion of a primary series or the most recent monovalent booster dose (regardless of the total number of previous booster doses received). Please refer to CDC's printable At-A-Glance COVID-19 Vaccination Schedules: www.cdc.gov/vaccines/covid-19/downloads/COVID-19-vacc-schedule-at-a-glance-508.pdf.
Always check the date at the bottom of the document after new changes are announced to be sure you are using the most current version. You may also verify whether you are using the most current documents by checking Immunize.org's regularly updated Checklist of Current Versions of U.S. COVID-19 Vaccination Guidance and Clinic Support Tools: www.immunize.org/catg.d/p3130.pdf.
If a patient does not come back on time for the second dose of an mRNA COVID-19 vaccine, do we need to re-start the vaccine series?
No. Regardless of the interval, simply administer the second dose to complete the primary series.
What if the patient gets the second dose of an mRNA COVID-19 vaccine early?
Primary series, additional primary series, or bivalent booster doses administered more than 4 days before the minimum recommended interval should be repeated after at least the recommended minimum interval between doses. Doses administered within a grace period of 4 days or fewer from the recommended date are considered valid and do not need to be repeated.
When considering timing of the repeat dose, CDC further explains that some experts suggest delaying a repeat dose for 8 weeks after an invalid dose based on the rare risk of myocarditis and pericarditis from mRNA and Novavax COVID-19 vaccines, particularly in groups at increased risk for myocarditis and pericarditis (e.g., males ages 1239 years). Individual risk for COVID-19 and the likelihood for an adverse event following vaccination should be taken into consideration when recommending a longer interval.
As of September 1, 2022, monovalent COVID-19 vaccines are no longer authorized for use as booster doses. If the vaccination history of a patient age 12 years or older shows that the patient received a monovalent COVID-19 booster dose too early, do not repeat it. Proceed with administration of the recommended bivalent booster dose at least 2 months after the most recent monovalent booster dose.
Since a dose of mRNA COVID-19 vaccine may be given up to 4 days before the recommended interval because of the 4-day grace period, should we offer appointments up to 4 days before the recommended interval routinely?
No. People should not be routinely scheduled to receive a dose earlier than recommended. Schedulers should offer appointments beginning on the date of the recommended interval or later. CDC guidance allows for doses to be given up to 4 days before the recommended interval in order to avoid missed vaccination opportunities when a recipient unexpectedly arrives early and might not return on schedule.
If a patient inadvertently received a different brand of monovalent vaccine as a second dose, does it need to be repeated with the correct brand?
No. Do not repeat the dose. Any combination of Moderna, Novavax, or Pfizer-BioNTech monovalent vaccines is considered a complete primary series provided the proper number of doses is administered. If Janssen vaccine is administered, this counts as a single-dose series and no more primary doses are indicated.
Children age 6 months through 4 years who receive different mRNA products for the first 2 doses of an mRNA COVID-19 vaccine series should follow a 3-dose schedule. A third dose of either mRNA vaccine should be administered 8 weeks after the second dose to complete the 3-dose primary series.
Children age 5 through 17 years who receive a mixed mRNA COVID-19 vaccine primary series can follow the Pfizer-BioNTech COVID-19 Vaccine schedule and receive a booster dose. Use a bivalent Pfizer-BioNTech booster dose for all recipients age 12 through 17 years.
A 3-year-old child in my practice who received a first dose of Moderna COVID-19 vaccine at an outside clinic just received a dose of Pfizer-BioNTech COVID-19 vaccine as dose 2 instead of the second dose of Moderna vaccine. Do we need to give another dose?
Children who are age 6 months through 4 years and receive different mRNA products for the first two doses need to follow a 3-dose schedule. The third dose of either mRNA vaccine should be administered 8 weeks after the second dose to complete the 3-dose primary series.
If a patient received a dose of Novavax COVID-19 Vaccine, but cannot locate a second dose of Novavax vaccine, what should we do?
CDC recommends that, in general, the same vaccine product should be used for all doses in the primary series.
In the following exceptional situations, a different, age-appropriate COVID-19 vaccine may be administered to complete a primary series at a minimum interval of 28 days from the last COVID-19 vaccine dose. No VAERS report is required.
The same vaccine is not available
The first dose is unknown
A person starts but is unable to complete a primary series with the same COVID-19 vaccine due to a contraindication.
People who receive Janssen COVID-19 Vaccine after a dose of another COVID-19 vaccine should be considered to have received a valid, single-dose Janssen primary series.
What are COVID-19 Vaccine Emergency Use Instructions (EUI) and to whom do they apply?
CDC has issued emergency use instructions (EUI) for the use of the monovalent FDA-licensed mRNA vaccines (adolescent/adult Pfizer-BioNTech COVID-19 Vaccine [Comirnaty] or Moderna COVID-19 Vaccine [Spikevax]) as primary series or additional doses that are beyond the FDA-approved package labeling for these products. The CDC-issued EUI provide information on the following uses of the COVID-19 vaccine:
A longer interval of up to 8 weeks between the first and second primary dose of monovalent mRNA COVID-19 vaccine for people age 12 years and older, particularly for individuals at higher risk of mRNA COVID- 19 vaccine-associated myocarditis
Delaying the second primary dose in people age 12 years and older who recently had SARS-CoV-2 infection by 3 months from symptom onset or positive test (if infection was asymptomatic)
Primary dose(s), including for those with certain immunocompromising conditions or those with incomplete primary series, for people age 12 years and older who received primary vaccination with certain non-FDA authorized or approved COVID-19 vaccines
An additional dose in people age 18 years and older with certain immunocompromising conditions who received primary vaccination with the Janssen (Johnson & Johnson) COVID-19 Vaccine.
Revaccination of moderately or severely immunocompromised people age 12 years and older who received certain therapies (indicated below) and received primary dose(s) of COVID-19 vaccine prior to or during treatment
°
Received COVID-19 vaccine dose(s) during treatment with B-cell-depleting therapies over a limited period
° Received COVID-19 vaccine dose(s) prior to or during treatment involving hematopoietic cell transplant (HCT) or chimeric antigen receptor (CAR)-T-cell therapy
All CDC EUI resources, including the Pfizer-BioNTech and Moderna EUI Fact Sheets for Healthcare Providers, as well as those for recipients and caregivers (available in English and Spanish), are at this site: www.cdc.gov/vaccines/covid-19/eui/index.html.
We have a patient who was vaccinated with a COVID-19 vaccine in another country. What do we do?
CDC has issued a detailed set of emergency use instructions (EUI) that provides a legal framework for the use of licensed COVID-19 vaccines to vaccinate people who have received vaccines not authorized or licensed in the United States. One important factor in determining next steps is whether or not the vaccine administered in another country is listed for emergency use by the World Health Organization (WHO-EUL), which signals that the vaccine has been reviewed and considered acceptable for use by WHO experts.
CDC has outlined each vaccination option on its website: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us-appendix.html#appendix-b.
A list of the vaccines that have already received WHO-EUL status is available here: https://extranet.who.int/pqweb/vaccines/vaccinescovid-19-vaccine-eul-issued.
My patient was vaccinated in a clinical trial with a vaccine that is not authorized for use by the FDA. How should we evaluate his need for vaccination now?
People vaccinated as part of a clinical trial with a vaccine not authorized or approved for use in the United States are covered under the CDC's Emergency Use Instructions (EUI).
CDC has provided specific guidance for evaluating the current vaccination needs of people who participated in a COVID-19 vaccine clinical trial here: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us-appendix.html#appendix-c.
What should be done if a patient scheduled for vaccination is exposed to COVID-19 or is isolated for suspected or confirmed SARS-CoV-2 infection?
An asymptomatic person who is scheduled for COVID-19 vaccination and is exposed to SARS-CoV-2 virus may be vaccinated but should wear a high-quality mask or respirator (e.g., N95) to prevent exposure of others at the vaccination site. If symptoms develop before the vaccination appointment, the person should isolate immediately, get tested, and stay home until results are known. If the results are positive, vaccination should be deferred until at least the end of the isolation period to avoid exposing vaccinators to the virus.
People who recently had SARS-CoV-2 infection may consider delaying a primary series dose or their bivalent COVID-19 vaccine booster dose by 3 months from symptom onset or positive test (if infection was asymptomatic). According to CDC, increasing the time between infection and vaccination may result in an improved immune response to vaccination. At this time, there is evidence of a low risk of reinfection in the weeks following infection. A recipient's individual risks for severe disease and current COVID-19 conditions in the community should be taken into account when deciding whether to delay vaccination up to 3 months after infection.
Can COVID-19 vaccine recipients be given other vaccines at the same visit?
Yes, with one exception, COVID-19 vaccines and other vaccines may be administered without regard to timing. Extensive experience with non-COVID-19 vaccines has demonstrated that the immune response and side effects following vaccination are generally similar when vaccines are administered simultaneously and when vaccines are administered alone.
The timing of COVID-19 vaccination following recent orthopoxvirus (e.g., monkeypox) vaccination is the one exception to the principle that COVID-19 vaccines may be administered without any regard to the timing of other vaccines. There is a small risk for myocarditis after receipt of ACAM2000 orthopoxvirus vaccine and an even more rare risk for myocarditis after receipt of mRNA COVID-19 vaccines (Moderna and Pfizer-BioNTech) or Novavax COVID-19 Vaccine. There is an unknown risk for myocarditis after Jynneos orthopoxvirus vaccination. For this reason, people, particularly adolescent or young adult males, might consider waiting 4 weeks after orthopoxvirus vaccination (either Jynneos or ACAM2000) before receiving a Moderna, Novavax, or Pfizer-BioNTech COVID-19 vaccine.
If an orthopoxvirus vaccine is recommended for a person to prevent infection in the setting of a monkeypox outbreak, orthopoxvirus vaccination should not be delayed because of recent receipt of a Moderna, Novavax, or Pfizer-BioNTech COVID-19 vaccine; no minimum interval between COVID-19 vaccination with these vaccines and vaccination with Jynneos or ACAM2000 is necessary.
My patient is due for a second dose of recombinant zoster vaccine (Shingrix, GSK). However, the patient is also due for a COVID-19 vaccine dose and wants to be vaccinated as soon as possible. What should we advise our patient about scheduling the second Shingrix dose?
Your patient may choose to receive the vaccines at the same visit or separately, without regard to the timing interval. In general, when deciding whether to coadminister other vaccines with COVID-19 vaccine, you should consider whether the patient is behind or at risk of becoming behind on recommended vaccines, their risk of vaccine-preventable disease (e.g., during an outbreak or occupational exposures), and the reactogenicity profile of the vaccines.
When multiple vaccines are administered at a single visit, administer each injection in a different injection site. For adolescents and adults, the deltoid muscle may be used for more than one injection, though injection sites should be at least one inch apart. It is generally preferable to administer reactogenic vaccines such as Shingrix and COVID-19 vaccine in different arms, if possible. If the patient prefers both injections in the same deltoid, that is also acceptable.
Immunize.org has developed a one-page guide to administering multiple intramuscular vaccinations to an adult at one visit: www.immunize.org/catg.d/p2030.pdf.
A patient had a routine tuberculin skin test (TST) placed the day before the patient's appointment for a COVID-19 vaccine. Should we proceed with vaccination or do we need to reschedule?
CDC advises that COVID-19 vaccination should not be delayed because of testing for tuberculosis (TB) infection. Testing for TB infection with one of the immune-based methods, either the tuberculin skin test (TST) or an interferon-gamma release assay (IGRA), can be done before, after, or during the same encounter as COVID-19 vaccination: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us.html#special-populations.
How does the use of monoclonal antibodies or convalescent plasma to treat or prevent COVID-19 affect the scheduling of COVID-19 vaccination?
In February 2022, CDC updated its guidance on the scheduling of COVID-19 vaccination around monoclonal antibodies or convalescent plasma. CDC now recommends that COVID-19 vaccination does NOT need to be delayed following receipt of monoclonal antibodies or convalescent plasma.
Administration of tixagevimab/cilgavimab (Evusheld, AstraZeneca) to moderately or severely immunocompromised people for pre-exposure prophylaxis (PrEP) is recommended every 6 months, in addition to vaccination. Wait two weeks after administering a COVID-19 vaccination to administer Evusheld, per the product's emergency use authorization. There is no minimum interval after administration of Evusheld to give a COVID-19 vaccine dose.
Contraindications and Precautions Back to top
Please describe the contraindications for each COVID-19 vaccination.
We refer our readers to CDC's updated set of contraindications and precautions to vaccination with COVID-19 vaccines, located in table 4 of its interim clinical considerations for the use of COVID-19 vaccines in the United States: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us.html#contraindications.
What are the precautions to COVID-19 vaccination?
We refer our readers to CDC's updated set of contraindications and precautions to COVID-19 vaccination, located in table 4 of its interim clinical considerations for the use of COVID-19 vaccines: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us.html#contraindications.
Can people who are immunocompromised or who have autoimmune disease be vaccinated with COVID-19 vaccines?
Yes, they may be vaccinated as long as they do not have a contraindication to vaccination. Antibody testing is not recommended to assess for immunity to SARS-CoV-2 following COVID-19 vaccination.
Recipients should be counseled about the unknown and variable effectiveness of COVID-19 vaccination in immunocompromised populations and the potential for reduced immune responses. They should maintain other practices, such as wearing a mask in public and avoiding crowds, to reduce their risk of exposure to SARS-CoV-2. Healthcare providers treating patients with moderate to severe immunocompromise who are not expected to respond effectively to vaccination should consider the use of Evusheld (AstraZeneca) antibody therapy every 6 months for pre-exposure prophylaxis.
The current immunization schedules for each available vaccine product for people ages 6 months or older with moderate or severe immunocompromise are listed in CDC's At-A-Glance COVID-19 Vaccination Schedules document: www.cdc.gov/vaccines/covid-19/downloads/COVID-19-vacc-schedule-at-a-glance-508.pdf.
CDC provides detailed considerations for vaccination of people with moderate or severe immunocompromise here: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us.html#immunocompromised.
Are there any common types of allergies that are neither contraindications nor precautions to vaccination?
Allergic reactions (including severe allergic reactions) not related to vaccines (COVID-19 or other vaccines) or injectable therapies, such as allergic reactions related to food, pet, venom, or environmental allergies, or allergies to oral medications (including the oral equivalents of injectable medications), are not a contraindication or precaution to COVID-19 vaccination. The vial stoppers of COVID-19 vaccines are not made with natural rubber latex, and there is no contraindication or precaution to vaccination for people with a latex allergy. COVID-19 vaccines do not contain eggs, gelatin, or metals.
A self-limited, delayed-onset local reaction around the injection site ("COVID arm") has been reported by some mRNA vaccine recipients several days after vaccination (see next question). This type of reaction is not a precaution or contraindication to future doses of the same vaccine.
A vaccine recipient reported experiencing a red, itchy, swollen patch of skin that developed several days after vaccination around the injection site of her first COVID-19 vaccine dose. It resolved after a few days. Is this a contraindication? Should this alter our plans for dose two?
This condition is not rare and is also known as "COVID arm". She should receive dose two as recommended. Individuals with only a delayed-onset local reaction (e.g., redness, induration, itching) around the injection site area after the first vaccine dose do not have a contraindication or precaution to the second dose.
These delayed-onset local reactions are sometimes quite large but are self-limited. It is not known whether individuals who experienced a delayed-onset injection site reaction after the first dose will experience a similar reaction after the second dose. However, these reactions are not believed to represent an increased risk for anaphylaxis after a subsequent dose. Thus, individuals with such delayed injection site reactions after the first mRNA COVID-19 vaccine dose should receive the second dose using the same vaccine product as the first dose and at the recommended interval, preferably in the opposite arm.
Patients who experience "COVID arm" may take an antihistamine if it is itchy or a pain medication such as acetaminophen or a non-steroidal anti-inflammatory (NSAID) if it is painful.
Patients concerned about the risk of allergic reaction or side effects following COVID-19 vaccination are asking if they should take acetaminophen, aspirin, and/or antihistamines before receiving COVID-19 vaccination. What does CDC advise?
Medications to reduce fever and pain (e.g., acetaminophen, non-steroidal anti-inflammatory drugs) may be taken to treat post-vaccination local or systemic symptoms, if medically appropriate. However, routine administration of such medications before vaccination is not recommended because information on the impact of such use on COVID-19 vaccine-induced antibody responses is not available at this time.
Administration of antihistamines before COVID-19 vaccination to prevent allergic reactions is not recommended. Antihistamines do not prevent anaphylaxis, and their use might mask cutaneous symptoms, which could delay diagnosis and management of anaphylaxis.
It is not recommended that people take aspirin or an anticoagulant before vaccination with the Janssen COVID-19 vaccine or any other FDA-authorized COVID-19 vaccine unless they take these medications as part of their routine medications.
Is COVID-19 vaccination contraindicated in a patient who has had immune-mediated thrombosis with thrombocytopenia syndrome (TTS)?
It is contraindicated to administer Janssen COVID-19 Vaccine to persons with a history of TTS following receipt of the Janssen COVID-19 Vaccine or any other adenovirus vector-based COVID-19 vaccines (e.g., AstraZeneca COVID-19 Vaccine, which is not authorized or approved in the United States). Individuals who have not received Janssen or AstraZeneca vaccine but have a history of an episode of an immune-mediated TTS, such as heparin-induced thrombosis with thrombocytopenia (HIT), should be offered an mRNA or Novavax COVID-19 vaccine for the primary series.
All clinical considerations concerning the use of Janssen COVID-19 Vaccine are available from CDC here: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us-appendix.html#appendix-a.
My patient has a history of deep venous thrombosis (DVTs). Is that a precaution or contraindication to vaccination with the Janssen COVID-19 Vaccine?
Venous thromboembolism (VTE), defined as deep vein thrombosis, pulmonary embolism, or both, are common. The biologic mechanisms for VTE (as well as arterial thrombi) differ from the underlying immune-mediated mechanism for thrombosis with thrombocytopenia syndrome (TTS). Experts believe that the presence of risk factors for VTE does not make individuals more susceptible to TTS after vaccination with the Janssen vaccine. As with the general population, other age-appropriate authorized or approved COVID-19 vaccines are preferred over Janssen vaccine for these recipients.
Is there a precaution or contraindication against vaccination of children or adults who have recovered from COVID-19 Multisystem Inflammatory Syndrome (MIS-C or MIS-A)?
There are limited data on the safety of COVID-19 vaccines in people who have had MIS-C or MIS-A from SARS-CoV-2 infection and who have not yet received COVID-19 vaccine. Case-by-case consultation with their clinical team or a specialist (e.g., specialist in infectious diseases, rheumatology, or cardiology) is strongly encouraged. CDC continues to update its clinical considerations for vaccination of children or adults who have experienced MIS-C or MIS-A. Visit this link for the most current clinical considerations for vaccination of children and adults who have experienced this syndrome following SARS-CoV-2 infection: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us.html#covid19-vaccination-misc-misa.
My patient had an episode of myocarditis 5 years ago. Is a history of myocarditis a contraindication or precaution to vaccination with an mRNA or Novavax vaccine?
CDC guidance is that people who have a history of completely resolved myocarditis or pericarditis unrelated to COVID-19 vaccination (e.g., due to SARS-CoV-2 or other viruses) may receive any age-appropriate COVID-19 vaccine that is FDA-approved or FDA-authorized. "Complete resolution" includes resolution of symptoms attributed to myocarditis or pericarditis, as well as no evidence of ongoing heart inflammation or sequelae as determined by the person's clinical team.
History of myocarditis or pericarditis after a dose of an mRNA (Pfizer-BioNTech or Moderna) COVID-19 vaccine or Novavax COVID-19 Vaccine is a precaution to vaccination with any COVID-19 vaccine, and subsequent doses should generally be avoided. For people who have a history of myocarditis associated with MIS-C or MIS-A, see CDC's interim clinical considerations concerning COVID-19 vaccination and MIS-C and MIS-A: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us.html#covid19-vaccination-misc-misa.
Complete and current clinical considerations for COVID-19 vaccination of patients with a history of myocarditis are available from CDC here: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us.html#myocarditis-pericarditis.
For additional information about myocarditis and mRNA COVID-19 vaccines, visit www.cdc.gov/vaccines/covid-19/clinical-considerations/myocarditis.html.
My patient has a history of Guillain-Barré syndrome (GBS). Is that a contraindication or precaution to vaccination with any COVID-19 vaccine?
People with a history of GBS can receive any currently FDA-authorized or licensed COVID-19 vaccine. Vaccine safety monitoring suggests an elevated risk of GBS in the 42 days following the Janssen COVID-19 Vaccine, with the highest risk observed in people ages 40 through 64 years. Most reports of GBS have been in males. The risk of this very rare outcome is clearly outweighed by the benefits of vaccination with a COVID-19 vaccine, including Janssen COVID-19 Vaccine in exceptional situations when vaccination with another COVID-19 vaccine is not possible.
Vaccine Safety Back to top
What common side effects are expected after vaccination with mRNA vaccines?
Recipients of mRNA COVID-19 vaccines often experience local (e.g., pain, swelling, redness at the injection site, localized swollen lymph nodes in the armpit of the vaccinated arm) or systemic (e.g., fever, fatigue, headache, chills, body and joint aches) post-vaccination symptoms. Depending on vaccine product (Pfizer-BioNTech vs. Moderna), age group, and vaccine dose, approximately 80–91% of vaccinated people develop at least one local symptom and 5591% develop at least one systemic symptom following vaccination.
Most systemic post-vaccination symptoms are mild to moderate in severity, occur within the first three days of vaccination, and resolve within 1–3 days of onset. These symptoms are more frequent and severe following the second dose and among younger people compared to older people.
Among children ages 6 months through 4 years (Pfizer-BioNTech) or 6 months through 5 years (Moderna), pain or tenderness at the injection site was the most frequent local reaction. The most common systemic symptom in older children was fatigue; in younger children (ages 6 through 23 months), irritability/crying and drowsiness/sleepiness were most common. Most systemic symptoms were mild to moderate in severity, typically began 1 to 2 days after vaccination, and resolved after 1 to 2 days.
What common side effects are expected after vaccination with Novavax COVID-19 Vaccine?
In clinical trials of Novavax COVID-19 Vaccine, pain or tenderness at the injection site was the most frequently reported local reaction among vaccine recipients; redness and swelling were reported less frequently. Fatigue, headache, and muscle pain were the most commonly reported systemic reactions. Most symptoms were mild to moderate in severity and resolved within 1 to 3 days. Overall, symptoms were more frequent in people ages 18 through 64 years compared to people ages 65 years and older and more frequent after dose 2 than dose 1.
What common side effects are expected after vaccination with Janssen COVID-19 Vaccine (Johnson & Johnson)?
Recipients of the Janssen viral vector vaccine in the phase 3 clinical trial often experienced local or systemic post-vaccination symptoms, though the majority of reported symptoms were mild to moderate in severity and resolved within 1 to 3 days after vaccination. The frequency of any local reaction was higher in participants aged 18 to 59 years than participants age 60 years or older (59.8% vs 35.4%). Pain at the injection site was the most frequently reported solicited local reaction. The frequency of systemic reactions was higher in participants age 18–59 years than participants 60 years or older (61.5% vs 45.3%). For both age groups, fatigue and headache were the most commonly reported systemic reactions. Fever was more common in participants 18–59 years (12.8%) compared to those 60 years or older (3.1%).
What is the thrombosis with thrombocytopenia syndrome, called TTS, associated with the Janssen COVID-19 Vaccine?
TTS is a rare, immune-mediated syndrome that involves acute venous or arterial thrombosis (blood clot) and new onset thrombocytopenia (low platelet count) in patients with no recent known exposure to heparin. The onset of TTS is typically 1 to 2 weeks following vaccination; treatment with heparin, a common anticoagulant used to treat blood clots, worsens the condition. In the U.S., the majority of people with TTS after Janssen COVID-19 vaccination had clots located in cerebral venous sinuses; clots occurred in other unusual locations including in the portal vein and splenic vein, and also included a combination of venous and arterial thromboses.
Cases of TTS following administration of the Janssen COVID-19 Vaccine have been reported in males and females, in a wide age range of individuals 18 years and older, with the highest reporting rate (approximately 1 case per 100,000 doses administered) in females ages 30-49 years; overall, approximately 15% of TTS cases have been fatal.
Based on an updated risk-benefit analysis, including the risk of TTS, use of mRNA COVID-19 vaccines is preferred over the Janssen COVID-19 vaccine for all vaccine-eligible people. The FDA EUA for Janssen vaccine limits its authorized use to people for whom mRNA vaccines are clinically inappropriate or those for whom mRNA vaccination is not feasible. All people who elect to receive a Janssen COVID-19 vaccine booster should be informed about the risk and symptoms of TTS that could occur after vaccination (typically within 2 weeks after receipt), the need to seek immediate medical care should such symptoms develop at any time, and the availability of mRNA COVID-19 vaccines instead of the Janssen COVID-19 Vaccine.
What are the symptoms of TTS and where can I learn more about treatment?
Cases of TTS following administration of the Janssen COVID-19 Vaccine have been reported in males and females, in a wide age range of individuals 18 years and older, with the highest reporting rate (approximately 1 case per 100,000 doses administered) in females ages 30-49 years; overall, approximately 15% of TTS cases have been fatal. Symptom onset typically begins 1 to 2 weeks after vaccination. People should seek medical attention right away if they have any of the following symptoms after receiving the Janssen vaccine:
Shortness of breath
Chest pain
Leg swelling
Persistent abdominal pain
Severe or persistent headaches or blurred vision
Easy bruising or tiny blood spots under the skin beyond the site of the injection
Treatment of TTS is different from the treatment of typical blood clots; heparin should be avoided in any patient suspected of TTS until the diagnosis can be ruled out.
For additional clinical guidance, see the CDC Health Alert Network Report from April 13, 2021: emergency.cdc.gov/han/2021/han00442.asp and treatment guidelines from the American Society for Hematology: www.hematology.org/covid-19/vaccine-induced-immune-thrombotic-thrombocytopenia.
Have any COVID-19 vaccines been associated with Guillain-Barré syndrome (GBS)?
Vaccine safety monitoring indicates an increased risk of GBS within 42 days of vaccination with the Janssen COVID-19 Vaccine, with the highest risk among people ages 40 through 64. Most reports have been in males. Although the chance of GBS occurring is extremely low, Janssen vaccine recipients should be counseled to seek medical attention promptly if symptoms of GBS occur, such as progressive muscle weakness. Currently, no association has been observed between GBS and mRNA COVID-19 vaccines.
Moderna or Pfizer-BioNTech mRNA COVID-19 vaccines or Novavax COVID-19 Vaccine are preferred for individuals with a history of GBS. A history of GBS is a precaution for receipt of Janssen vaccine.
Patients who experienced GBS within 6 weeks after Janssen COVID-19 vaccination should not receive future doses of Janssen COVID-19 vaccine. They should be informed of the recommendation for a booster dose 2 months after the first dose and the option to receive an mRNA vaccine for booster doses. Discussions with the clinical team for the patient are encouraged to assist decision-making.
I have both mRNA and Janssen vaccines available. Now that FDA has limited the use of Janssen vaccine, when should I offer the Janssen vaccine?
Use of monovalent mRNA COVID-19 vaccines and Novavax vaccine is preferred over Janssen COVID-19 Vaccine as a primary vaccination for all vaccine-eligible people except in situations where use of an alternative vaccine is not feasible, as described below:
When there is a contraindication to mRNA and Novavax COVID-19 vaccines
When a person would otherwise remain unvaccinated for COVID-19 due to lack of access to mRNA or Novavax COVID-19 vaccines
When a person refuses mRNA and Novavax primary series vaccination and chooses to receive the Janssen COVID-19 Vaccine despite the safety concerns identified
Monovalent vaccines, including Janssen, are no longer authorized for use as booster doses. All people who elect to receive a Janssen COVID-19 Vaccine primary dose should be informed about the risk and symptoms of TTS that could occur after vaccination (typically within 2 weeks after receipt), the need to seek immediate medical care should such symptoms develop at any time, and the availability of mRNA and Novavax COVID-19 vaccines instead of the Janssen COVID-19 Vaccine.
Can COVID-19 vaccination lead to fertility problems?
There is no evidence that any of the COVID-19 vaccines affect current or future fertility.
Tell me about mRNA COVID-19 vaccines and the risk of myocarditis and pericarditis.
A rare risk for myocarditis (inflammation of the heart muscle) and/or pericarditis (inflammation of the tissue surrounding the heart) has been observed following receipt of mRNA COVID-19 vaccines and Novavax COVID-19 Vaccine.
Among mRNA vaccine recipients, these rare cases of myocarditis or pericarditis have occurred most frequently in adolescent and young adult males within the first week after receiving the second dose of an mRNA COVID-19 vaccine. The risk appears lower following a booster dose. Myocarditis has been even more rarely reported in children younger than age 12 years after COVID-19 vaccination. Most patients with myocarditis after mRNA COVID-19 vaccination have been hospitalized for short periods, with most completely recovering from their acute symptoms. CDC is assessing long-term outcomes in people with myocarditis after mRNA COVID-19 vaccination.
People receiving mRNA vaccines, especially males age 12 through 39, should be counseled about the risk of myocarditis or pericarditis and advised to seek medical attention promptly if they develop chest pain, shortness of breath, or feelings of a fast, fluttering, or pounding heartbeat.
Cases of myocarditis and pericarditis were identified in clinical trials of Novavax COVID-19 Vaccine and have also been reported during post-authorization use outside the United States. These findings suggest that an increased risk for these conditions may be present after receiving Novavax COVID-19 vaccine.
Evidence from other countries indicates that waiting 8 weeks to administer the second mRNA dose can significantly reduce the risk of myocarditis following dose 2; antibody levels after dose 2 may also be higher when given after an 8-week interval. CDC now recommends that an 8-week interval between dose 1 and dose 2 may be optimal for some people age 6 months through 64 years, especially adolescent and young adult males. CDC does not recommend the 8-week dose interval for people who need rapid protection from COVID-19, including adults 65 or older, people with moderate to severe immunocompromise, and in circumstances where rapid protection is desired due to high levels of circulating COVID-19.
CDC's complete interim clinical considerations for COVID-19 vaccination and myocarditis or pericarditis are available here: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us.html#myocarditis-pericarditis.
CDC also has published additional clinical considerations for the evaluation and care of patients with myocarditis or pericarditis following mRNA vaccination: www.cdc.gov/vaccines/covid-19/clinical-considerations/myocarditis.html.
How should patients with allergies presenting for COVID-19 vaccination be evaluated?
Serious allergic reactions, such as anaphylaxis, in the minutes following vaccination are rare but are possible with any vaccine. Every vaccination site should have staff available who are trained and equipped to recognize and respond to signs of anaphylaxis in a vaccine recipient. See this CDC website for additional information about preparing for the management of anaphylaxis: www.cdc.gov/vaccines/covid-19/clinical-considerations/managing-anaphylaxis.html?anaphylaxis-management.html.
Anaphylaxis following vaccination with mRNA COVID-19 vaccines is reported at a rate of approximately 2 to 5 cases per million doses administered.
An immediate severe allergic reaction to any component or previous dose of an mRNA COVID-19 vaccine is a contraindication to vaccination with both the Pfizer-BioNTech and Moderna vaccines (monovalent and bivalent formulations); however, use of the Novavax or Janssen vaccines may not be contraindicated; see the CDC's COVID-19 interim clinical considerations section on contraindications and precautions for details: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us.html#contraindications.
This CDC chart of vaccine components is designed to assist the triage of patients with various health conditions or allergies: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us-appendix.html#appendix-e.
How long should patients be observed for signs of an immediate allergic reaction following vaccination with a COVID-19 vaccine?
In accordance with general best practices for vaccination, all people should be observed for at least 15 minutes after vaccination for signs of an immediate allergic reaction.
If you vaccinate a person who has a precaution to COVID-19 vaccination, you should consider a 30-minute observation period following vaccination. For complete CDC guidance on the triage and management of individuals with a history of allergies or allergic reactions, please consult this CDC table: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us-appendix.html#appendix-e.
Where can I find the latest information on allergic reactions and COVID-19 vaccines?
Visit this CDC website for the latest information: www.cdc.gov/coronavirus/2019-ncov/vaccines/safety/allergic-reaction.html.
For information about how to triage and manage people with a history of allergy who present for COVID-19 vaccination, see CDC's triage guidance: www.cdc.gov/vaccines/covid-19/clinical-considerations/interim-considerations-us-appendix.html#appendix-e.
I have heard that the FDA has specific reporting requirements for healthcare providers who administer COVID-19 vaccines under EUA. What are they?
Adverse events that occur in a recipient following COVID-19 vaccination should be reported to VAERS. Vaccination providers are required by FDA and the provider agreement for the CDC COVID-19 Vaccination Program to report the following that occur after COVID-19 vaccination:
Vaccine administration errors whether or not associated with an adverse event
Serious adverse events, irrespective of attribution to vaccination
Cases of Multisystem Inflammatory Syndrome (MIS) in adults and children
Cases of myocarditis after a Pfizer-BioNTech or a Moderna vaccine
Cases of pericarditis after a Pfizer-BioNTech or a Moderna vaccine
Cases of COVID-19 that result in hospitalization or death
Reporting is encouraged for any other clinically significant adverse event, even if it is uncertain whether the vaccine caused the event. Information on how to submit a report to VAERS is available at https://vaers.hhs.gov or by calling 1-800-822-7967.
How is the safety of COVID-19 vaccines being monitored?
Multiple national surveillance systems are being used to monitor the safety of new COVID-19 vaccines in different ways. Please see this CDC website for additional information on each system: www.cdc.gov/coronavirus/2019-ncov/vaccines/safety.html.
What is v-safe?
CDC's v-safe program is a smartphone-based tool that uses text messaging and web surveys to provide personalized health check-ins after a person receives a COVID-19 vaccination. It also provides second dose reminders. Participation is voluntary; pregnant individuals are especially encouraged to participate in the v-safe pregnancy registry. Vaccine recipients may sign up for the program after receiving the first dose. For more information, visit www.cdc.gov/coronavirus/2019-ncov/vaccines/safety/vsafe.html.
Is compensation for an injury resulting from an EUA COVID-19 vaccine available through the National Vaccine Injury Compensation Program (VICP)?
No. The COVID-19 vaccines are not part of the VICP. The COVID-19 vaccines are part of a similar program called the Countermeasures Injury Compensation Program (CICP). For more information, visit this web page: www.hrsa.gov/cicp.
Storage and Handling Back to top
Where can I find details about the storage and handling of COVID-19 vaccines?
You may find guidance on the storage and handling of each authorized or licensed COVID-19 vaccine in the CDC's Vaccine Storage and Handling Toolkit addendum on COVID-19 vaccines: www.cdc.gov/vaccines/hcp/admin/storage/toolkit/storage-handling-toolkit.pdf.
CDC has produced a printable quick reference guide summarizing the storage and handling requirements for each authorized COVID-19 vaccine. The storage and handling requirements of bivalent products are the same as monovalent products of the same brand and formulation. Storage and handling requirements are unchanged by the addition of a new strain.
Pfizer-BioNTech COVID-19 Vaccine:
°
Gray cap monovalent and bivalent products (age 12+ years): www.cdc.gov/vaccines/covid-19/info-by-product/pfizer/downloads/gray-cap-storage-summary.pdf
° Orange cap monovalent (age 5 through 11 years): www.cdc.gov/vaccines/covid-19/info-by-product/pfizer/downloads/Pfizer_PED_StorageHandling_Summary.pdf
° Maroon cap monovalent (age 6 months through 4 years): www.cdc.gov/vaccines/covid-19/info-by-product/pfizer/downloads/infant-storage-handling-summary.pdf
Moderna COVID-19 Vaccine (all formulations in one document): www.cdc.gov/vaccines/covid-19/info-by-product/moderna/downloads/Moderna-Storage-Summary-508.pdf
Novavax COVID-19 Vaccine:
www.cdc.gov/vaccines/covid-19/info-by-product/novavax/downloads/novavax-storage-handling-summary.pdf
Janssen COVID-19 Vaccine:
www.cdc.gov/vaccines/covid-19/info-by-product/janssen/downloads/janssen-storage-handling-summary.pdf
Immunize.org has assembled key COVID-19 vaccine storage and handling resources in its section on Clinic Resources and Tools at our "Vaccines: COVID-19" main page: www.immunize.org/covid-19/#tools.
Under what conditions may we transport COVID-19 vaccines? Is transport of a partial vial or predrawn syringe ever permissible?
Although routine transportation of vaccines to different facilities is not generally recommended, there are times when this is necessary. CDC recommends transporting COVID-19 vaccine in vials and always with a continuous temperature monitoring device to ensure adherence to authorized storage times and temperatures. Because liquid mRNA COVID-19 vaccines should not be shaken vigorously, it is preferred to transport vials in their solid frozen state or to initiate transport while frozen, if they are not already thawed. Never re-freeze vaccine that is already thawed. Moderna recommends that thawed vials of liquid be cushioned to minimize agitation during transport. A partially used vial may be transported (e.g., in the process of vaccinating homebound individuals), but cannot be transferred from one provider to another nor can it be transported across state lines. Details are provided in the 2022 CDC Vaccine Storage and Handling Toolkit addendum on COVID-19 vaccines: www.cdc.gov/vaccines/hcp/admin/storage/toolkit/storage-handling-toolkit.pdf.
There may be instances when the only option is to transport vaccine in a predrawn syringe. CDC refers to the U.S. Pharmacopeia (USP) guidance for transporting predrawn vaccine in syringes in the USP COVID-19 Vaccine Toolkit: Operational Considerations for Healthcare Practitioners. The complete document provides detailed guidance on COVID-19 vaccine transport and is available for download from this site: www.usp.org/covid-19/vaccine-handling-toolkit.
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This page was updated on September 8, 2022.
This page was reviewed on September 8, 2022.
 
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VACCINATING ADULTS:
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This website is supported in part by a cooperative agreement from the National Center for Immunization and Respiratory Diseases (Grant No. 1NH23IP922654) at the Centers for Disease Control and Prevention (CDC) in Atlanta, GA. The website content is the sole responsibility of IAC and does not necessarily represent the official views of CDC.