Questions about mRNA COVID-19 Vaccines
Q: Should people who have had COVID-19 illness be vaccinated?
A: Yes. Vaccination should be offered to individuals regardless of history of prior SARS-CoV-2 infection. 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.
As with all vaccines, vaccination should be deferred until after recovery from moderate to severe COVID-19 illness. In addition, to minimize the risk of exposing others to SARS-CoV-2 virus, vaccination generally should be deferred until criteria have been met for individuals with COVID-19 illness to discontinue isolation.
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Q: Can COVID-19 vaccine recipients be given other vaccines at the same visit?
A: There are no data on the safety and efficacy of mRNA COVID-19 vaccines administered with any other vaccine. For this reason, CDC currently recommends that the mRNA COVID-19 vaccine series should be administered alone, and not within 14 days before or after any other vaccination. However, mRNA COVID-19 and other vaccines may be administered at shorter intervals if the benefits of vaccination are judged to outweigh any unknown potential risks of vaccine coadministration. Examples of such situations include tetanus vaccination as a part of wound management, vaccination in response to a measles or hepatitis A outbreak, or COVID-19 vaccination of a person in a long-term care facility or healthcare setting who recently received influenza or other vaccinations (to avoid delays or missed opportunities for COVID-19 vaccination). If mRNA COVID-19 vaccines are administered within 14 days of another vaccine, doses do not need to be repeated for either vaccine.
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Q: My patient is due for a second dose of recombinant zoster vaccine (Shingrix, GSK). However, the patient is eligible to receive COVID-19 vaccine and wants to be vaccinated against COVID-19 as soon as possible. What should we advise our patient about scheduling the second Shingrix dose?
A: Advise your patient to schedule the second Shingrix dose at least 14 days after receiving the second mRNA COVID-19 vaccination.
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Q: If the second dose of vaccine may be given before the recommended interval because of the 4-day grace period, should we offer that option routinely?
A: No. CDC states that people should not be scheduled to receive dose 2 earlier than recommended (21 days for Pfizer-BioNTech, 28 days for Moderna). Schedulers should offer second dose appointments beginning on the date of the recommended interval or later. CDC guidance allows for dose 2 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. The series never needs to be restarted due to a delay in the second dose.
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Q: A patient had a routine tuberculin skin test (TST) placed the day before the patient’s appointment for a first dose of COVID-19 vaccine. Should we proceed with vaccination or do we need to reschedule?
A: COVID-19 vaccination may take place on the same day or any day after a TST is placed. A TST will not interfere with the response to vaccination. The reliability of a TST is expected to be unchanged if a TST is placed before or simultaneously with COVID-19 vaccination. The reliability of a negative TST or interferon gamma release assay (IGRA) soon after COVID-19 vaccination has not been studied.
COVID-19 vaccination should not be delayed because of testing for tuberculosis (TB) infection. A TST is not a vaccine and is not subject to the general recommendation for an interval of at least 14 days between mRNA COVID-19 vaccination and administration of any other vaccine. If not administered on the same day, CDC recommends that a TST be delayed at least 4 weeks after completion of COVID-19 vaccination because the reliability of a negative TST result soon after mRNA COVID-19 vaccination is unknown.
For additional details on mRNA COVID-19 vaccination of patients being evaluated for active tuberculosis, refer to CDC clinical considerations for mRNA vaccines and laboratory testing: www.cdc.gov/vaccines/covid-19/info-by-product/clinical-considerations.html#laboratory-testing
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Q: How does the use of monoclonal antibodies to treat symptomatic COVID-19 affect the scheduling of mRNA COVID-19 vaccination?
A: There are no data on the effect of passive antibody therapies for COVID-19, including monoclonal antibodies and convalescent plasma, on the effectiveness of vaccination with mRNA COVID-19 vaccines. As a precautionary measure, CDC recommends waiting at least 90 days after receipt of passive antibody therapy for COVID-19 illness before initiating the COVID-19 vaccine series. Individuals who develop COVID-19 illness after the first COVID-19 vaccination and receive passive antibody therapy should wait 90 days after antibody therapy to receive the second dose. There is no need to restart the vaccination series.
Antibody therapies not specific to COVID-19 treatment (e.g., intravenous immunoglobulin, RhoGAM) are unlikely to substantially impair development of a protective antibody response to COVID-19 vaccination. Thus, there is no recommended minimum interval between antibody therapies not specific to COVID-19 treatment and mRNA COVID-19 vaccination.
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Q: Patients concerned about the risk of allergic reaction or side effects following COVID-19 vaccination are asking if they should take acetaminophen and/or antihistamines before receiving mRNA COVID-19 vaccination. What does CDC advise?
A: 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 currently recommended because information on the impact of such use on mRNA COVID-19 vaccine-induced antibody responses is not available at this time.
In addition, administration of antihistamines before mRNA 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.
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Q: Please describe the contraindications for COVID-19 mRNA vaccination.
A: CDC considers a history of the following to be a contraindication to vaccination with both the Pfizer-BioNTech and Moderna COVID-19 vaccines:
- Severe allergic reaction (e.g., anaphylaxis) after a previous dose of an mRNA COVID-19 vaccine or any of its components
- Immediate allergic reaction of any severity to a previous dose of an mRNA COVID-19 vaccine or any of its components (including polyethylene glycol [PEG])*
- Immediate allergic reaction of any severity to polysorbate (due to potential cross-reactive hypersensitivity with the vaccine ingredient PEG)*
*These people should not receive mRNA COVID-19 vaccination at this time unless they have been evaluated by an allergist-immunologist and it is determined that they can safely receive the vaccine (e.g., under observation, in a setting with advanced medical care available).
CDC has published a table with additional details about the components of both mRNA COVID-19 vaccines: www.cdc.gov/vaccines/covid-19/info-by-product/clinical-considerations.html#Appendix-C
People with an immediate allergic reaction to the first dose of an mRNA COVID-19 vaccine should not receive additional doses of either of the mRNA COVID-19 vaccines. CDC has provided a chart to assist in the evaluation of immediate reactions to vaccination: www.cdc.gov/vaccines/covid-19/info-by-product/clinical-considerations.html#Appendix-D.
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Q: What are the precautions to COVID-19 mRNA vaccination?
A: CDC considers a history of any immediate allergic reaction to any other vaccine or injectable therapy (defined as intramuscular, intravenous, or subcutaneous vaccines or therapies [excluding subcutaneous immunotherapy for allergies, known as “allergy shots”] not related to a component of mRNA COVID-19 vaccines or polysorbate) as a precaution but not a contraindication to vaccination for both the Pfizer-BioNTech and Moderna COVID-19 vaccines. These precautions based on history, as defined, include people with a reaction to a vaccine or injectable therapy that contains multiple components, one of which is PEG, another vaccine component, or polysorbate, but in whom it is unknown which component caused the immediate allergic reaction.
Individuals with a precaution to vaccination should be counseled about the unknown risks of experiencing a severe allergic reaction and balance these risks against the benefits of vaccination. Deferral of vaccination and/or consultation with an allergist-immunologist may be considered until further information on the risk of anaphylaxis is available.
The following considerations can be used to help assess the risk for mRNA COVID-19 vaccination in these individuals:
- Risk of exposure to SARS-CoV-2
- Risk of severe disease or death due to COVID-19
- Whether the patient has previously been infected with SARS-CoV-2 and, if so, how long ago; because reinfection is uncommon in the months following infection, a person with a precaution to vaccination and recent COVID-19 illness may choose to delay vaccination until further information is known about the risk of anaphylaxis following vaccination
- The unknown risk of anaphylaxis following mRNA COVID-19 vaccination in a person with a history of an immediate allergic reaction to other vaccines or injectable therapies
- Ability of the patient to be vaccinated in a setting where appropriate medical care is immediately available for anaphylaxis
For additional guidance about contraindications and precautions, please refer to www.cdc.gov/vaccines/covid-19/info-by-product/clinical-considerations.html#Contraindications
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Q: Are there any common types of allergies that are neither contraindications nor precautions to vaccination?
A: Allergic reactions (including severe allergic reactions such as anaphylaxis) that are not related to vaccines, injectable therapies, components of mRNA COVID-19 vaccines (including PEG), or polysorbates are not a contraindication or precaution to vaccination with either mRNA COVID-19 vaccine. Examples of other allergies that are not a contraindication or precaution include other food, pet, venom, or environmental allergies, or allergies to oral medications (including the oral equivalents of injectable medications). The vial stoppers of these mRNA vaccines are not made with natural rubber latex, so there is no contraindication or precaution to vaccination for persons with a latex allergy. In addition, mRNA COVID-19 vaccines do not contain eggs or gelatin.
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Q: A vaccine recipient reported experiencing a red, itchy, swollen patch of skin that developed several days after vaccination around the injection site of the patient’s first Moderna vaccine dose. It resolved after a few days. Is this a contraindication? Should this alter our plans for dose two?
A: 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. Some people have reported delayed-onset local reactions, including Moderna clinical trial participants, beginning a few days through the second week after the first dose. The 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.
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Q: Under what conditions may we transport mRNA COVID-19 vaccines? Is transport of a partial vial or predrawn syringe ever permissible?
A: Although routine transportation of vaccines to different facilities is not generally recommended, there are times when this is necessary. CDC recommends transporting mRNA 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, if possible, or to initiate transport while they are frozen. Moderna recommends that thawed vials of liquid be cushioned to minimize agitation during transport. Thawed vaccine should never be refrozen. 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 2021 CDC Vaccine Storage and Handling Toolkit addendum on mRNA 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 on page 11 of the USP COVID-19 Vaccine Toolkit: Operational Considerations for Healthcare Practitioners. The complete document provides detailed guidance on mRNA COVID-19 vaccine transport and is available for download from this site: www.usp.org/covid-19/vaccine-handling-toolkit.
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Q: What is v-safe?
A: 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. 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.
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Q: Has CDC provided clinical guidance on what to do if an error occurs while administering mRNA COVID-19 vaccinations?
A: Yes. On February 10, 2021, CDC published a new appendix to its “Interim Clinical Considerations for Use of mRNA Vaccines Currently Authorized in the United States.” This appendix provides resources for preventing and reporting mRNA COVID-19 vaccine administration errors, as well as a simple table outlining actions to take after an error has occurred: www.cdc.gov/vaccines/covid-19/info-by-product/clinical-considerations.html#Appendix-A.
Errors addressed include the following:
- Incorrect route or site
- Incorrect age
- 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 vaccine
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