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Administering Vaccines
Billing and Reimbursement
Combination Vaccines
Contraindications and Precautions
COVID-19 and Routine Vac
Documenting Vaccination
Hepatitis A
Hepatitis B
Meningococcal ACWY
Meningococcal B
Scheduling Vaccines
Storage and Handling
Travel Vaccines
Vaccine Recommendations
Vaccine Safety
Varicella (chickenpox)
Zoster (shingles)
Disease Issues Contraindications and Precautions
Vaccine Recommendations Live Attenuated Influenza Vaccine (LAIV) Issues
For Children Administering Vaccines
For Special Groups Storage and Handling
For Health Care Personnel (HCP)
Disease Issues
How serious a problem is influenza in the U.S.?
Influenza is the most frequent cause of death from a vaccine-preventable disease in the United States. Rates of infection from seasonal influenza are highest among children, but the risks for complications, hospitalizations, and deaths are higher among adults age 65 years and older, children younger than 5 years, pregnant women, and people of any age who have medical conditions that place them at increased risk for complications from influenza.
In a study of influenza seasons from 1976–77 through 2006–07, the estimated number of annual influenza-associated deaths from respiratory and circulatory causes ranged from a low of 3,349 (1985–86 season) to a high of 48,614 (2003–2004 season), with an average of 23,607 influenza-associated deaths. In addition to fatalities, seasonal influenza was also responsible for more than 200,000 hospitalizations per year.
A novel H1N1 virus was first detected in March 2009 and quickly spread to pandemic levels. In the U.S., it is estimated that approximately 43–89 million persons became ill with 2009 pandemic H1N1 from April 2009 to April 2010. The virus also resulted in significant hospitalizations and deaths among children, adults age 19–65 years, obese persons, and pregnant and post-partum women. The pandemic virus has continued to circulate.
From the 2010–11 through the 2019–20 seasons, the annual influenza-related disease burden has varied from approximately 9–56 million illnesses, 4–26 million medical visits, 140,000–810,000 hospitalizations and 12,000–62,000 deaths per year.* The number of influenza laboratory confirmed deaths in children reported to CDC has averaged 132 deaths (range 37–188) per year. This is considered an underestimate of actual pediatric deaths as some influenza-related deaths are likely not reported or recognized. For more information on the health burden of influenza, see www.cdc.gov/flu/about/burden/index.html.
* Estimates from 2017–20 are preliminary. These estimates include median estimates for all years except for 2019–20 season where the 95% confidence interval is included as the median estimate is not yet published.
What medical conditions increase the risk of severe illness from influenza?
While even healthy children and adults can get severe influenza or die from influenza and its complications, the risk of severe influenza is higher for children younger than 5 years, adults 50 years and older, pregnant women, Alaska Natives and American Indians, and residents of nursing homes or other long-term care facilities. Medical conditions that increase a person's risk of severe influenza include chronic pulmonary (including asthma), cardiovascular (excluding isolated hypertension), renal, hepatic, neurologic, hematologic, or metabolic disorders (including diabetes mellitus); immunocompromising conditions due to any cause (including but not limited to immune suppression caused by medications or HIV); extreme obesity (body mass index of >40 for adults); and the chronic use of aspirin- or salicylate-containing medications in children through age 18 (due to the risk of Reye syndrome after influenza infection).
How do risk groups for severe illness from influenza and SARS-CoV-2 compare to each other?
People of all ages are susceptible to illness from both influenza and SARS-CoV-2, the virus that causes COVID-19. High risk groups for severe illness from influenza and SARS-CoV-2 substantially overlap. While we continue to learn more about COVID-19, currently CDC identifies persons at increased risk of severe COVID www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/index.html as older adults, with risk increasing as age increases; and persons with cancer, chronic kidney disease, COPD (chronic obstructive pulmonary disease), immunocompromised state (weakened immune system) from solid organ transplant, obesity (body mass index [BMI] of 30 or higher), serious heart conditions (such as heart failure, coronary artery disease, or cardiomyopathies), sickle cell disease, or type 2 diabetes.
Groups that might be at an increased risk for severe illness from COVID-19 include asthma (moderate to severe), cerebrovascular disease, cystic fibrosis, hypertension, immunocompromised due to treatment or medical conditions, neurologic conditions (such as dementia), liver disease, pregnancy, pulmonary fibrosis (having damaged or scarred lung tissues), smoking, thalassemia (a type of blood disorder), and type 1 diabetes mellitus.
More information about risk factors for severe COVID-19 can be found at: www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/index.html.
Can influenza viruses circulate at the same time as SARS-CoV-2, the virus that causes COVID-19?
Yes. Both viruses co-circulated at the start of the COVID-19 pandemic and continue to circulate, although the number of influenza viruses detected in the U.S. decreased substantially in the spring of 2020. The extent to which SARS-CoV-2 and influenza viruses will co-circulate during this upcoming influenza is unknown, however, CDC anticipates that both viruses will circulate during the 2020–21 influenza season.
Where can I get information on influenza and its surveillance?
Information regarding influenza surveillance is available year-round from CDC at www.cdc.gov/flu/weekly/fluactivitysurv.htm. The full FluView surveillance report is published each Friday afternoon from October through mid-May and an abbreviated FluView report is published Mid-May through September. In addition, periodic updates about influenza are published in MMWR.
State and local health departments should be consulted regarding availability of influenza vaccine, access to vaccination programs, information about state or local influenza activity, and for reporting influenza outbreaks and receiving advice regarding their control.
Vaccine Recommendations Back to top
What's new in the 2020–21 influenza vaccine recommendations?
The 2020–21 ACIP influenza vaccine recommendations were published on August 21, 2020, and are available at www.cdc.gov/mmwr/volumes/69/rr/pdfs/rr6908a1-H.pdf. The updated guidance describes the vaccine composition for this season (a change in the A/H3N2, A/H1N1, and B/Victoria lineage vaccine components); discusses the availability of two new vaccines for adults age 65 and older, Fluzone High-Dose Quadrivalent (Sanofi Pasteur) and Fluad Quadrivalent (Seqirus); updates recommended intervals between live attenuated influenza vaccine (LAIV4, Flumist Quadrivalent; AstraZeneca) and influenza antiviral medications; updates contraindications for LAIV4 to include cerebral spinal fluid leak, cochlear implant, and anatomic or functional asplenia; and updates guidance on vaccination of people with severe allergic reaction to eggs to state that vaccination in a medical setting supervised by a healthcare provider who is able to recognize and manage severe allergic reaction is needed only if administering a vaccine other than cell culture-based quadrivalent influenza vaccine (Flucelvax Quadrivalent; Seqirus) or recombinant hemagglutinin influenza vaccine (Flublok Quadrivalent; Sanofi Pasteur).
Who is recommended to be vaccinated against influenza?
ACIP recommends annual vaccination for all people ages 6 months and older who do not have a contraindication to influenza vaccination.
Which influenza vaccines will be available during the 2020–21 influenza season?
Multiple manufacturers are producing influenza vaccine for the U.S. market for the 2020–21 season. Inactivated influenza vaccines will be produced using egg-based, cell culture-based, and recombinant technologies. Live attenuated nasal spray vaccine (Flumist Quadrivalent; AstraZeneca) will also be available. All but one influenza vaccine will be quadrivalent (containing four strains of influenza virus). The only trivalent vaccine available is the MF-59 adjuvanted vaccine (Fluad; Seqirus), however a quadrivalent MF-59 adjuvanted vaccine is also available (Fluad Quadrivalent; Seqirus). Both Fluad vaccines are indicated for adults age 65 years and older.
ACIP does not state a preference for one influenza vaccine over another for people for whom more than one vaccine is recommended for their age and health condition. A complete listing of influenza vaccine products is available at www.immunize.org/catg.d/p4072.pdf.
What are the new influenza vaccines available for the 2020–21 influenza season?
Fluzone High-Dose Quadrivalent (HD-IIV4, Sanofi Pasteur) and Fluad Quadrivalent (Seqirus), both for adults 65 years and older, are new for 2020–21. The HD-IIV4 replaces Fluzone High-Dose (trivalent). Both Fluad Quadrivalent and Fluad (trivalent) will be available this season.
HD-IIV4, Fluad (trivalent), and Fluad Quadrivalent are supplied as pre-filled syringes. A dose of HD-IIV4 is 0.7 mL; the dose of both Fluad and Fluad Quadrivalent vaccines is 0.5 mL.
What are the changes to vaccine viruses for the 2020–21 influenza season?
Influenza vaccines produced for the current season will mostly be quadrivalent (four components). Quadrivalent vaccines contain two A viruses and two B viruses while trivalent vaccines contain two A viruses and one B virus.
For the 2020–21 season, U.S. egg-based influenza vaccines (i.e., vaccines other than Flucelvax Quadrivalent and Flublok Quadrivalent) will contain hemagglutinin (HA) derived from an influenza:
A/Guangdong-Maonan/SWL1536/2019 (H1N1)pdm09-like virus,
A/Hong Kong/2671/2019 (H3N2)-like virus,
B/Washington/02/2019 (Victoria lineage)-like virus, and
B/Phuket/3073/2013 (Yamagata lineage)-like virus (for quadrivalent vaccines).
U.S. cell culture-based (Flucelvax Quadrivalent) and recombinant (Flublok Quadrivalent) influenza vaccines will contain HA derived from an influenza:
A/Hawaii/70/2019 (H1N1)pdm09-like virus,
• A/Hong Kong/45/2019 (H3N2)-like virus,
• B/Washington/02/2019 (Victoria lineage)-like virus, and
• B/Phuket/3073/2013 (Yamagata lineage)-like virus.
If quadrivalent vaccines includes one additional strain, why aren't they preferred for use over trivalent vaccines?
Two different types of influenza B virus are likely to cause disease during an influenza season, but trivalent influenza vaccines contain only one type of influenza B virus. The quadrivalent vaccine includes both types of B virus. While most vaccines are now quadrivalent, not all types of vaccine are likely to be uniformly available in any practice setting or locality. Consequently, ACIP does not express a preference for use of one type of influenza vaccine over another type (that is, quadrivalent over trivalent) for those for whom more than one type of vaccine is indicated and available. Vaccination should not be delayed in order to obtain a specific product when an appropriate one is already available.
Is it acceptable to administer a dose of the quadrivalent influenza vaccine to a patient who has already received the trivalent vaccine? We've had a few patients request this.
No. ACIP does not recommend more than one dose of influenza vaccine in a season, except for certain children age 6 months through 8 years for whom two doses are recommended.
When should influenza vaccines be given?
CDC recommends that vaccination should be offered by the end of October. Vaccination should continue throughout the influenza season, including into the spring months (for example, through May), as long as influenza viruses are circulating and providers have unexpired vaccine.
Children age 6 months to 8 years without two prior doses of influenza vaccine need 2 doses. They should get their first influenza vaccination as soon as vaccine becomes available; the minimum interval for the second dose is 28 days.
For people who need only 1 dose, early vaccination (i.e., July and August) can result in reduced immune protection towards the end of the influenza season, particularly for older adults.
To avoid missed opportunities for vaccination, providers should offer vaccination during routine healthcare visits and hospitalizations. Early vaccination of children younger than age 9 years who need 2 doses of vaccine can be helpful in assuring routine second doses are given before the influenza season begins.
We are unsure about when to start our influenza vaccination promotion, and when to ideally vaccinate our patients. Does protection from seasonal influenza vaccine decline or wane during the influenza season? Should I wait until later in the year to vaccinate my elderly or medically frail patients?
Optimally, vaccination should occur before onset of influenza activity in the community. Because the timing of the onset, peak, and decline of influenza activity varies, the ideal time to start vaccinating cannot be predicted each season. Local outbreaks can begin as early as October, but CDC reports that 75% of influenza seasons peak in January or later.
CDC recommends that vaccination should be offered by the end of October. Children age 6 months to 8 years without two prior doses of flu vaccine need 2 doses and should get their first influenza vaccination as soon as vaccine becomes available to ensure they are fully vaccinated before the onset of community outbreaks.
Several studies have reported decreases in vaccine effectiveness over the influenza season. However, waning effects have not been observed consistently across age groups, virus subtypes, and seasons. While delaying vaccination might permit greater immunity later in the season, deferral could result in missed opportunities to vaccinate, as well as difficulties in vaccinating a large number of people within a more limited time period.
For people who need only 1 dose, early vaccination (i.e., July and August) can result in reduced immune protection towards the end of the influenza season, particularly for older adults.
Should our practice consider revaccinating our high risk and older patients a second time during the year due to concerns with waning immunity?
For people who have already been fully vaccinated, revaccination later in the season is not recommended.
How late in the season can I vaccinate my patients with influenza vaccine?
Peak influenza activity generally occurs in the Northern Hemisphere in January or February. Providers should continue vaccinating patients throughout the influenza season, including into the spring months (for example, through May), as long as they have unexpired vaccine in stock and unvaccinated patients in their office.
Because influenza occurs in many areas of the world during April through September, vaccine should be given to travelers who missed vaccination in the preceding fall and winter. Another late season use of vaccine is for children younger than age 9 years who needed 2 doses of vaccine but failed to get their second dose. For each of these situations, vaccine can be given through the month of June since most injectable influenza vaccine has a June 30 expiration date.
What types of personal protective equipment do healthcare personnel need for administering vaccines in light of COVID-19?
CDC recommends that healthcare personnel administering any vaccines during COVID-19 wear surgical masks and eye protection (goggles or face shields). N95 respirators are not recommended. Gloves are recommended when giving intranasal or oral vaccines because of the increased likelihood of coming into contact with a patient's mucous membranes and body fluids. Gloves are optional for other vaccines. Importantly, hands should be washed and gloves, when worn, should be changed between each patient. See the CDC web page Vaccination Guidance During a Pandemic www.cdc.gov/vaccines/pandemic-guidance/index.html for additional details.
We are considering co-locating our COVID-19 drive-through testing site and influenza vaccination sites. Can we vaccinate someone with suspected or confirmed COVID-19 infection?
CDC recommends deferring vaccination for people with suspected or confirmed COVID-19 until they have met criteria for no longer needing quarantine or isolation to avoid exposing healthcare personnel and other patients. When scheduling or confirming appointments for vaccination, patients should be screened for COVID-19 symptoms and recent exposure.
Which travelers are recommended to be vaccinated?
Healthcare providers should vaccinate any person who failed to get vaccinated in the previous vaccination season and who wants to reduce their risk of acquiring influenza during their upcoming travel, particularly if they are at high risk for influenza-related complications. This includes persons who are traveling to the tropics, traveling with organized tourist groups at any time of year, or traveling to the Southern Hemisphere during April–September.
If a patient received a dose of influenza vaccine in June (for example, for international travel), how long should the patient wait before getting vaccinated with the next season's flu vaccine?
There should be a minimum of 4 weeks between the doses in such situations.
If an unvaccinated patient who has just recovered from a laboratory confirmed case of influenza comes into our clinic, should we vaccinate him?
Yes. Influenza vaccine contains three or four influenza vaccine virus strains; two A viruses and one or two B viruses, which are prepared based on circulating viruses from the previous influenza season. Infection from one virus type does not confer immunity to other types and it would not be unusual to be exposed to more than one type during a typical influenza season. So, a person who has recently had influenza will benefit from receipt of a vaccine that contains additional influenza virus strains.
How long does immunity from influenza vaccine last?
Protection from influenza vaccine is thought to persist for at least 6 months. Protection declines over time because of waning antibody levels and because of changes in circulating influenza viruses from year to year. For people who need only 1 dose of influenza vaccine for the season, yearly vaccination (i.e. in July and August) is likely to be associated with suboptimal immunity before the end of the influenza season, particularly among older adults.
Some of my patients refuse influenza vaccination because they insist they "got the flu" after receiving the injectable vaccine in the past. What can I tell them?
There are several reasons why this misconception persists:
    Less than 1% of people who are vaccinated with the injectable vaccine develop flu-like symptoms, such as mild fever and muscle aches, after vaccination. These side effects are not the same as having influenza, but people confuse the symptoms.
    Protective immunity doesn't develop until 1–2 weeks after vaccination. Some people who get vaccinated later in the season (December or later) may be infected with influenza virus shortly afterward. These late vaccinees develop influenza because they were exposed to someone with the virus before they became immune. It is not the result of the vaccination.
    For many people, "the flu" is any illness with fever and cold symptoms or gastrointestinal symptoms. If they get any viral illness, they may blame it on flu vaccine or think they got "the flu" despite being vaccinated. Influenza vaccine only protects against certain influenza viruses, not all viruses.
    Influenza vaccination is our best protection against influenza disease; however, some people who are vaccinated will still contract influenza illness despite vaccination.
While vaccine effectiveness (VE) can vary, recent studies show that flu vaccination reduces the risk of flu illness by between 40% and 60% among the overall population during seasons when most circulating flu viruses are well-matched to the flu vaccine. VE is generally lower for adults age 65 years and older. Influenza vaccination has also been shown to reduce influenza disease severity even if someone does get sick after vaccination, and reduces the risk of influenza hospitalization, and deaths in children and adults. Influenza vaccination also reduces the risk of acute cardiac events, like heart attack and heart failure, among people with heart disease.
For more information on this topic, go to: www.cdc.gov/flu/professionals/vaccination/effectivenessqa.htm.
When administering influenza vaccine, is giving patients a vaccine information statement (VIS) mandatory or is it only "recommended"?
Giving patients an influenza Vaccine Information Statement (VIS) is mandatory under the National Childhood Vaccine Injury Act of 1986. The VIS must be given to all adults as well as to parents or guardians of children prior to vaccination. Two VISs are available, one for live attenuated influenza vaccine (LAIV) and one for inactivated influenza vaccine (IIV) and recombinant vaccine (RIV). Each can be found at www.immunize.org/vis/ in multiple languages. The latest influenza vaccine VISs are dated August 15, 2019, and should be used until updated VISs are available from CDC. CDC allows providers to use VISs that they have already printed when updates become available.
The latest VIS for all vaccines plus translations in multiple languages are located on the IAC website www.immunize.org/vis/.
Are there recommendations for the prevention of institutional outbreaks of influenza?
The most important factor in preventing outbreaks is annual vaccination of all residents and staff who work at facilities such as nursing homes, assisted living facilities, and other group living situations. Groups that should be targeted include physicians, nurses, and other personnel in hospitals and outpatient settings who have contact with high-risk patients in all age groups, and providers of home care to high-risk persons (for example, visiting nurses, therapists, and volunteers).
We are trying to provide influenza vaccination to all eligible patients during their stay in our hospital. If a patient does not remember if he or she has already received the vaccine this season, should we go ahead and vaccinate?
If a patient or family member cannot remember if the patient received influenza vaccine this season and no record is available, proceed with administering influenza vaccine, even if it might mean an extra dose is given. When a patient reports that they HAVE received influenza vaccine but does not have written documentation, ACIP states that in the specific case of influenza (and pneumococcal polysaccharide) vaccination, patient self-report of being vaccinated can be accepted as evidence of vaccination.
Live Attenuated Influenza Vaccine (LAIV) Issues Back to top
For whom is Flumist Quadrivalent approved?
Flumist Quadrivalent (LAIV4; AstraZeneca) is currently approved by FDA only for use among healthy non-pregnant persons age 2 through 49 years.
Is administering Flumist an aerosol-generating procedure requiring airborne precautions during the COVID-19 pandemic?
No. Giving Flumist is not considered an aerosol-generating procedure. See the CDC web page Vaccination Guidance During a Pandemic for additional details.
How is Flumist administered?
The vaccine dose (0.2 mL) comes inside a special sprayer device. A plastic clip on the plunger divides the dose into two equal parts. The patient is seated in an upright position with head tilted back. Half of the contents of the sprayer (0.1 mL) is sprayed into each nostril.
Can Flumist be administered to persons with minor acute illnesses, such as a mild upper respiratory infection (URI) with or without fever?
Yes, unless clinical judgment suggests nasal congestion is present that might impede delivery of the vaccine to the nasopharyngeal mucosa, in which case deferral of administration should be considered until the congestion resolves.
Can a woman who is breastfeeding receive Flumist?
Breastfeeding is not a contraindication for any routine vaccination including Flumist.
Can Flumist be given to contacts of immunosuppressed patients?
Like other live vaccines, Flumist should not be administered to immunosuppressed persons. ACIP has stated a preference for using inactivated influenza vaccine for household members, healthcare personnel, and others who have close contact with severely immunosuppressed individuals (for example, patients with hematopoietic stem cell transplants) during those periods in which the immunosuppressed person requires care in a protective environment because of the theoretical risk that the live attenuated vaccine virus could be transmitted to the severely immunosuppressed individual and cause disease. Healthcare personnel or other persons who have close contact with persons with lesser degrees of immunosuppression (for example, persons with diabetes, persons with asthma taking corticosteroids, or persons infected with human immunodeficiency virus) who are otherwise eligible for Flumist may receive it. No special precautions need to be taken by the vaccinated person.
How long after someone is vaccinated with Flumist must they stay away from a severely immunosuppressed person (a person who is hospitalized in protective [reverse] isolation)?
Persons should avoid contact with any person who is severely immunosuppressed for at least 7 days after receiving Flumist. There are no restrictions on being in contact with any other patients.
Is Flumist contraindicated for adults with asthma?
Asthma is a precaution for Flumist in people 5 years of age and older.
Can we give Flumist to a person who is taking an influenza antiviral medication?
An antiviral drug active against influenza virus may reduce the effectiveness of Flumist. ACIP has recommended different intervals between the last dose of an antiviral medication and Flumist administration, based upon the half-life of the antiviral medication. The new recommendations are as follows:
  Oseltamivir or zanamivir: wait at least 48 hours after last dose before administering Flumist
Peramivir: wait at least 5 days before administering Flumist
Baloxavir: wait at least 17 days before administering Flumist
If any influenza antiviral medication must be given within 14 days of Flumist administration, the patient should be revaccinated without delay with any age-appropriate inactivated influenza vaccine. All inactivated influenza vaccines and recombinant influenza vaccine (Flublok) may be administered at any time relative to antiviral medication.
One of our young patients made it impossible to administer the second part of the Flumist dose. What should we do?
A half dose of Flumist (or any other vaccine) is a non-standard dose and should not be counted. If you were unable to give the second half of the vaccine at that same appointment, you will have to provide another full dose of influenza vaccine at another time. Alternatively, you can give inactivated influenza vaccine any time after this partial dose. If you want to give Flumist again, you should wait four weeks, as it is a live vaccine.
For Children Back to top
Which children should receive influenza vaccine?
ACIP recommends annual influenza vaccination for all children age 6 months and older who do not have a contraindication to the vaccine.
Which influenza vaccines can we give to children?
Four injectable inactivated influenza vaccines are now approved by FDA for children age 6 months and older.
  Fluzone Quadrivalent (Sanofi Pasteur),
FluLaval Quadrivalent (GSK),
Fluarix Quadrivalent (GSK), and
Afluria Quadrivalent (Seqirus).
The inactivated cell culture-based influenza vaccine Flucelvax (Seqirus) is approved for people age 4 years and older.
The nasal spray live attenuated influenza vaccine, Flumist Quadrivalent (AstraZeneca), is approved for healthy people age 2–49 years who are not pregnant. Information about all influenza vaccines available in the U.S., including product billing codes, is available in IAC's handout titled "Influenza Vaccine Products for the 2020–2021 Influenza Season" at www.immunize.org/catg.d/p4072.pdf. Information on vaccine products for the U.S. is also available on CDC's website at www.cdc.gov/flu/professionals/vaccines.htm.
Please provide details about the use of inactivated influenza vaccine in children younger than 3 years.
Afluria Quadrivalent (Seqirus) dosing is 0.25 mL given IM for children age 6–35 months and 0.5 mL for children age 3 years and older.
The dosing for FluLaval Quadrivalent (GSK) and Fluarix Quadrivalent (GSK) vaccines is 0.5 mL for children age 6 months and older.
For Fluzone Quadrivalent (Sanofi Pasteur), either 0.25 mL or 0.5 mL doses can be given to children age 6–35 months. For children age 3 years and older, the dose is 0.5 mL.
Flucelvax Quadrivalent (Seqirus) is recommended beginning at age 4 years at 0.5 mL dose, but should not be used for children younger than age 4 years.
Which children younger than age 9 years will need 2 doses of influenza vaccine in this influenza season?
Children age 6 months through 8 years should receive a second dose 4 weeks or more after the first dose 1) if they are receiving influenza vaccine for the first time, 2) if they did not receive a total of at least two doses of any seasonal influenza vaccine before July 1 of the current year, or 3) if their vaccination history is unknown. The two previous doses need not have been received during the same season or consecutive seasons.
IAC's handout titled "Guide for Determining the Number of Doses of Influenza Vaccine to Give to Children Ages 6 Months Through 8 Years" provides guidance on this issue; it is available at www.immunize.org/catg.d/p3093.pdf.
When determining whether a child age 2 through 8 years needs one or two doses of influenza vaccine this season, can we count doses of Flumist administered in past years?
CDC advises that doses of Flumist administered in past seasons can be counted.
If a child age 8 years or younger has had one dose of trivalent and one dose of quadrivalent influenza vaccine in the past, do they need one or two doses for the upcoming season?
They need just one dose of any age and health condition-appropriate influenza vaccine annually.
Can a child age 6–35 months who needs 2 doses of influenza vaccine this season receive a combination of Afluria, Fluzone, FluLaval, Fluarix, or Flumist vaccine?
Yes. The two doses do not have to be the same brand. Afluria Quadrivalent (0.25 mL per dose), Fluzone Quadrivalent (0.25 mL or 0.5 mL per dose), FluLaval Quadrivalent (0.5 mL per dose), and Fluarix Quadrivalent (0.5 mL per dose) are approved by the FDA for use in children age 6–35 months. If a child is age 2 years or older, Flumist Quadrivalent may also be used when age and health condition are appropriate.
Can a child 36 months through 8 years of age who needs 2 doses of influenza vaccine this season receive a combination of Fluzone, FluLaval, Fluarix or Afluria vaccine?
Yes. The two doses do not have to be the same brand. Fluzone Quadrivalent (0.5 mL dose), FluLaval Quadrivalent (0.5 mL dose), Fluarix Quadrivalent (0.5 mL dose) and Afluria Quadrivalent (0.5 mL dose) are approved by the FDA for use in children age 3 years and older.
If a child receives Fluzone Quadrivalent vaccine (0.25 mL) at age 34 or 35 months for the first time and then returns for the second dose at age 37 months, should we give another 0.25 mL dose of Fluzone Quadrivalent or should we give the 0.5 mL dose that is indicated for age 3 years and older?
The child should always receive the dose appropriate for his or her age at the time of the clinic visit; at age 37 months that would be 0.5 mL.
Can a clinic vaccinate children younger than age 3 years with influenza vaccine taken from a multi-dose vial of influenza vaccine? The multi-dose vials contain thimerosal as a preservative.
Yes. Multi-dose vials of inactivated influenza vaccine contain a small amount of thimerosal to prevent bacterial and fungal growth in the vial. Thimerosal-containing vaccines are safe to use in children. No scientific evidence indicates that thimerosal in vaccines causes adverse events unless the patient has a severe allergy to thimerosal. However, a few states have enacted legislation that restricts the use of thimerosal-containing vaccines in children. To find out if your state has such restrictions, check with your state immunization program (see www.immunize.org/coordinators for contact information).
Do any children age 9 years and older need two total doses during an influenza season?
Yes. A 9-year-old should receive a dose of influenza vaccine if they turned 9 years old during the current season and already received one dose during the current season when they were 8 years old, AND they did not receive a total of at least two prior doses of influenza vaccine before July 1 of the current year, or if their vaccination history is unknown before July 1 of the current year.
There is a debate within my clinical department about not allowing influenza vaccine to be given with DTaP and PCV13. Are there data that state these should not be given concomitantly?
A CDC study has shown a small increased risk for febrile seizures during the 24 hours after a child receives the inactivated influenza vaccine at the same time as the PCV13 vaccine or DTaP vaccine. However, the risk of febrile seizure with any combination of these vaccines is small and ACIP recommends giving these vaccines at the same visit if indicated. See www.cdc.gov/vaccinesafety/concerns/febrile-seizures.html for more information.
For Special Groups Back to top
Is influenza vaccine recommended for pregnant women?
Yes. It is especially important to vaccinate pregnant women because of their increased risk for influenza-related complications and their baby's increased risk of influenza-related illness and hospitalizations during the first 6 months of life.
Influenza vaccination during pregnancy reduces mothers' risk of influenza illness, preterm labor, and their infants' risk of influenza and influenza-related hospitalization in the first 6 months of life.
Most studies of influenza vaccination in pregnant women have administered vaccine in the second or third trimester using inactivated influenza vaccine.
Vaccination can occur in any trimester, including the first. Only inactivated or recombinant influenza vaccines can be given to pregnant women. Flumist, a live vaccine, should not be used in pregnant women.
Why do we vaccinate pregnant women against influenza when it is not recommended to vaccinate infants younger than age 6 months?
ACIP has recommended vaccinating pregnant women with inactivated influenza vaccine since 1997. Pregnant women are at increased risk for complications, hospitalization, and even death from influenza because of the increased physiologic strain of pregnancy on their heart, lungs, and immune system. Vaccination can occur in any trimester, including the first.
Influenza vaccine is not recommended for children younger than age 6 months because it is not approved for this age group. However, vaccinating during pregnancy provides maternal antibodies to the fetus; this helps protect the young infant against influenza during the first 6 months of life. Vaccinating pregnant women protects women, their unborn babies, and their babies after birth.
Does ACIP recommend one influenza product over another for pregnant women?
Pregnant women can receive any inactivated or recombinant influenza vaccine. They should not be given Flumist Quadrivalent.
Can thimerosal-containing vaccine be given to pregnant women?
Yes, unless you live in a state that has enacted legislation restricting use in pregnant women. There is no scientific evidence that thimerosal in vaccines, including influenza vaccines, is a cause of adverse events, unless the patient has a systemic allergy to thimerosal.
If a patient was vaccinated earlier in the influenza season and later becomes pregnant during the same season, should she be revaccinated due to her pregnancy?
No. The Advisory Committee on Immunization Practices (ACIP) does not recommend more than one dose of influenza vaccine per season, except for certain children being vaccinated for the first time.
I heard that a study suggested an increase in miscarriage among women who received inactivated influenza vaccine. Please provide details.
A CDC-funded study found that women who had been vaccinated early in pregnancy with an influenza vaccine containing the pandemic H1N1 (H1N1pdm09) component and who also had been vaccinated the prior season with an H1N1pdm09-containing influenza vaccine had an increased risk of spontaneous abortion (miscarriage) in the 28 days after vaccination. This study did not quantify the risk of miscarriage and did not prove that influenza vaccine was the cause of the miscarriage. Earlier studies have not found a link between influenza vaccination and miscarriage. A larger follow-up study also funded by CDC which included 3 more years of data found no association between early miscarriage and influenza vaccination regardless of previous influenza season vaccination. These results are reassuring regarding the safety of influenza vaccination of pregnant women.
CDC, ACIP, and the American College of Obstetricians and Gynecologists (ACOG) have not changed the recommendation for influenza vaccination of pregnant women. It is recommended that pregnant women receive influenza vaccine during any trimester of their pregnancy because influenza poses a danger to pregnant women and the vaccine can prevent influenza in pregnant women and their infants.
A co-worker of mine says we are supposed to give infants preservative-free influenza vaccine. Is this true?
No. CDC and ACIP express no preference for preservative-free vaccine for infants or any other group of vaccine recipients.
No scientific evidence exists that thimerosal in vaccines, including influenza vaccines, is a cause of adverse events, unless the patient has a systemic allergy to thimerosal. However, some states have enacted legislation that restricts the use of thimerosal-containing vaccines. Check with your state immunization manager to see if your state is one of them (www.immunize.org/coordinators).
Do people with diabetes who control their disease with diet need influenza vaccine?
People with a metabolic disease, including diabetes, should receive annual influenza vaccination with an inactivated or recombinant influenza vaccine.
Is influenza vaccine safe to administer to patients with multiple sclerosis?
Yes. Multiple sclerosis is not a contraindication to any vaccine, including influenza and pneumococcal vaccines.
Does influenza vaccine increase the HIV titer in the blood of people with HIV infection?
Although some studies have demonstrated a transient increase in replication of HIV following inactivated influenza vaccine, other studies have not found this. This temporary increase in HIV titer has not been associated with deterioration in either T-lymphocyte counts or clinical condition. ACIP believes that annual influenza vaccination with inactivated vaccine will benefit many HIV-infected persons.
Please tell me about Fluad, one of the influenza vaccines for people age 65 years and older.
In November 2015, FDA licensed Fluad (aIIV3, Seqirus), a trivalent, MF59-adjuvanted inactivated influenza vaccine, for people age 65 years and older. Fluad is the first adjuvanted influenza vaccine marketed in the U.S. An adjuvant is a substance added to a vaccine to increase its immunogenicity. The MF59 adjuvant is based on squalene, an oil that occurs naturally in many plants and animals. Fluad has been used in Europe since 1997 and is approved in 38 other countries. Fluad is available as a trivalent and quadrivalent formulation. In contrast to Fluzone High-Dose Quadrivalent (Sanofi Pasteur), Fluad is a standard-dose vaccine, containing 15 mcg of hemagglutinin per virus per dose. In a small observational study among adults age 65 years and older Fluad was about 63% more effective than unadjuvanted trivalent standard dose inactivated influenza vaccine. ACIP has not stated a preference for any specific licensed influenza vaccine for people age 65 years and older.
A study published in 2014 found that the injectable vaccine Fluzone High-Dose protected people 65 years and older better than standard-dose Fluzone. Does ACIP preferentially recommend use of Fluzone High-Dose for all people age 65 years and older?
Aging decreases the body's ability to develop a good immune response after getting influenza vaccine, which places older people at greater risk of severe illness from influenza. A higher dose of antigen in the vaccine should give older people a better immune response and therefore provide better protection against influenza. There is published evidence of better protection from Fluzone High-Dose when compared to standard-dose Fluzone (N Engl J Med 2014; 371:635–45); however, ACIP has not stated a preference for any specific licensed influenza vaccine for people age 65 years and older.
Should Fluzone High-Dose Quadrivalent, Fluad, or Fluad Quadrivalent be administered to patients younger than age 65 years?
No. These three vaccines are licensed only for people age 65 years and older and are not recommended for younger people.
Sometimes patients age 65 years and older who have received the standard-dose influenza vaccine hear about the high-dose (Fluzone High-Dose Quadrivalent) or adjuvanted vaccine (Fluad or Fluad Quadrivalent) and want to receive that, too. Is this okay to administer?
No. ACIP does not recommend that anyone receive more than one dose of influenza vaccine in a season except for certain children age 6 months through 8 years for whom two doses are recommended.
Would giving an older patient 2 doses of standard-dose influenza vaccine be the same as administering the high-dose product?
No, and this is not recommended.
If a patient is undergoing treatment for cancer, is it safe to vaccinate her or him against influenza?
People with cancer need to be protected from influenza, and they can and should receive inactivated or recombinant influenza vaccine (but not live nasal spray vaccine [Flumist]) even if they are immunosuppressed. Cancer patients and survivors are at higher risk for complications from influenza, including hospitalization and death. Here is a helpful CDC web page on cancer and influenza for patients: www.cdc.gov/cancer/flu.
How soon after bone marrow transplant do we start to vaccinate our patients against influenza?
Inactivated influenza vaccine or recombinant influenza vaccine should be administered beginning at least 6 months after bone marrow transplant and annually thereafter for the life of the patient. A dose of vaccine can be given as early as 4 months after transplant, but a second dose should be considered in this situation. A second dose is recommended routinely for all children younger than 9 years receiving influenza vaccine for the first time.
For Health Care Personnel (HCP) Back to top
Why is influenza vaccination important for HCP? We already encourage them to stay home from work when they are sick.
Unfortunately, by the time a HCP has symptoms of influenza, they may have already exposed many patients since the virus is shed for 1–2 days before symptoms begin. Further, many studies show that HCP often go to work while they are sick and may be infectious to others. Start planning early to make sure all employees in your work setting receive annual influenza vaccination before the influenza season begins.
What are the ACIP recommendations for influenza vaccination of HCP?
Because HCP provide care to patients at high risk for complications of influenza, they should be considered a high-priority group for receiving vaccination. Achieving high rates of vaccination among HCP will protect staff and their patients, and reduce disease burden and healthcare costs. Vaccination rates of HCP are still too low; overall only 81% of HCP report influenza vaccination during the 2018–19 season.
Influenza vaccination key points for HCP include:
All HCP should be educated regarding the benefits of influenza vaccination.
Influenza vaccine should be administered annually to all eligible HCP.
A signed declination should be obtained from HCP who decline influenza vaccination.
Healthcare facilities should monitor HCP influenza vaccination coverage and declination at regular intervals.
HCP vaccination coverage should be used as one measure of a patient-safety quality program.
In 2011, ACIP published "Immunization of Health-Care Personnel," includes information about all recommended vaccines (see www.cdc.gov/mmwr/pdf/rr/rr6007.pdf).
Which health care personnel should be vaccinated against influenza?
It is important to vaccinate all healthcare personnel, including paid and unpaid workers who may be exposed to patients or infectious materials. This includes direct patient care staff (e.g., physicians, nurses, and therapists), and staff and volunteers in pharmacy, radiology, laboratory, human resources, facilities management (housekeeping), food services, and laundry. Vaccination should include healthcare staff in all settings, such as hospitals, outpatient clinics, pharmacies, emergency response, nursing homes and assisted living facilities, and home care.
Which employees of congregate living facilities, such as assisted living facilities and nursing homes, should be vaccinated against influenza?
All persons working in long-term care facilities who do not have a valid contraindication should receive annual influenza vaccination.
What is the Joint Commission's recommendation on vaccinating healthcare workers against influenza?
In January 2007, a new infection control standard of the Joint Commission became effective that requires accredited organizations to offer annual influenza vaccination to staff, volunteers, and licensed independent practitioners who have close patient contact.
I would like to help establish a policy of mandatory influenza vaccination for HCP in our facility and would like to learn from others. Can you help?
Every year more healthcare facilities are adopting mandatory vaccination policies for their employees. IAC has included many of these on its Honor Roll for Patient Safety, which gives special recognition to institutions that enforce mandatory vaccination for all personnel who are in the vicinity of a patient (for example, volunteers and housekeeping staff). To read about the policies of the various facilities included in the Honor Roll, go to www.immunize.org/honor-roll/influenza-mandates/honorees.asp. In addition, the National Adult and Influenza Immunization Summit has developed tools to assist post-acute and long-term care facilities that plan to implement influenza vaccination requirements for HCP at www.izsummitpartners.org/naiis-workgroups/influenza-workgroup/tools-for-ltcf/. We hope reviewing these policies and tools will give you the information you need to assist in developing a policy for your facility.
We have a mandatory vaccination policy in our facility; however, we allow employees to choose not to be vaccinated after filling out and signing an informed declination form. What can we do to achieve assurances that patient safety is still maintained?
Though vaccination is the most effective means of protecting your patients from influenza, there may be instances where employees are not vaccinated for medical or personal reasons. In these instances, you may want to consider reassigning unvaccinated workers to non-patient areas or requiring that they wear masks throughout the influenza season.
I heard about a hospital where more than 95% of employees received influenza vaccine last year. How did they achieve such a high level of vaccination?
Many hospitals across the U.S. have implemented successful influenza vaccination programs for their healthcare workers. One example is the Virginia Mason Medical Center in Seattle, WA that has consistently achieved high levels of vaccination among their employees and volunteers. A report covering the first 5 years of their program was published in the September 2010 issue of Infection Control and Hospital Epidemiology; an abstract of the report is available online at www.ncbi.nlm.nih.gov/pubmed/20653445.
Does the federal law that requires providing patients with VISs apply when administering influenza vaccine to employees and volunteers in hospitals or other workplaces?
If a vaccine is covered under the National Childhood Vaccine Injury Act—and almost all vaccines routinely administered to adults are (with the exception of PPSV and zoster)—it is mandatory under federal law to give the VIS for that vaccine to the vaccinee. Therefore, when you give influenza vaccine to employees and staff, you are required by law to provide them with a VIS.
Why does CDC recommend that we consider obtaining a signed declination from HCP who refuse influenza vaccination?
Some studies have shown an increase in HCP influenza vaccine acceptance when decliners are required to sign such a statement. In addition, such statements can help a vaccination program assess the reasons for declination and plan future educational efforts. IAC has posted the following suggested declination form for healthcare workers at www.immunize.org/catg.d/p4068.pdf.
Please tell me which professional associations have endorsed mandatory influenza vaccination for HCP and have created policy statements.
There are many professional associations that have issued policy statements supporting mandatory healthcare worker influenza vaccination. You can find information about these organizations as well as a list of more than 500 healthcare settings that have implemented mandatory vaccination programs on IAC's website at IAC's Influenza Vaccination Honor Roll web section at www.immunize.org/honor-roll/influenza-mandates/.
Contraindications and Precautions Back to top
What are contraindications and precautions for inactivated influenza vaccines?
Contraindications to inactivated influenza vaccines are a severe allergic reaction to a prior dose of influenza vaccine or a severe allergy to an influenza vaccine component (except egg).
Precautions to inactivated influenza vaccine include moderate or severe acute illness, and history of Guillain-Barré syndrome within 6 weeks after a dose of influenza vaccine.
What are contraindications and precautions for the recombinant influenza vaccine (Flublok)?
Contraindications to Flublok include history of severe allergic reaction to any component of the vaccine.
Precautions include moderate or severe acute illness, and history of Guillain-Barrι syndrome within 6 weeks after a dose of influenza vaccine.
What are the contraindications and precautions for Flumist?
Contraindications are:
a history of severe allergic reaction to a vaccine component (except egg—see next question) or after a previous dose of any influenza vaccine
concomitant aspirin or salicylate-containing therapy in children and adolescents because of the risk of Reye syndrome
children age 2 through 4 years who have received a diagnosis of asthma or whose parents or caregivers report that a healthcare provider has told them during the preceding 12 months that their child had wheezing or asthma or whose medical record indicates a wheezing episode during the preceding 12 months
immunosuppression due to any cause including medications or HIV infection
cerebral spinal fluid (CSF) leak, cochlear implant, or anatomic asplenia or functional asplenia (e.g., due to sickle cell anemia)
close contacts and caregivers of severely immunosuppressed persons who require a protected environment (e.g., reverse isolation in a hospital)
receipt of influenza antiviral medication within the previous 48 hours for oseltamivir and zanamivir, previous 5 days for peramivir, and previous 17 days for baloxavir
Precautions are:
moderate or severe acute illness with or without fever
history of Guillain-Barré syndrome within 6 weeks after a dose of influenza vaccine
asthma in a person age 5 years or older
underlying medical conditions that might predispose to complications after influenza virus infection, such as chronic pulmonary, cardiovascular (except isolated hypertension), renal, hepatic, neurologic, hematologic, or metabolic disorders including diabetes mellitus
What is the latest ACIP guidance on influenza vaccination and egg allergy?
ACIP recommends that people with a history of egg allergy who have experienced only hives after exposure to egg should receive influenza vaccine without specific precautions (except a 15-minute observation period for syncope). Any age-appropriate vaccine may be used. For people who report having had an anaphylactic reaction to egg (more severe than hives), if a vaccine other than Flucelvax Quadrivalent (ccIIV, Seqirus) or Flublok Quadrivalent (RIV4, Sanofi Pasteur) is given, the vaccine should be administered in an inpatient or outpatient medical setting supervised by a healthcare provider who is able to recognize and manage severe allergic conditions. Although not specifically recommended by ACIP, providers may prefer administering an age-appropriate egg-free vaccine (ccIIV4 or RIV4) for patients with severe egg allergy.
A previous severe allergic reaction to influenza vaccine, regardless of the component suspected to be responsible for the reaction, is a contraindication to future receipt of the vaccine. For a complete list of vaccine components (i.e., excipients and culture media) used in the production of the vaccine, check the package insert (available at www.immunize.org/fda) or go to www.cdc.gov/vaccines/pubs/pinkbook/downloads/appendices/B/excipient-table-2.pdf.
For more details about giving influenza vaccine to people with a history of egg allergy, see the ACIP guidance at www.cdc.gov/mmwr/volumes/69/rr/pdfs/rr6908a1-H.pdf. You also may find the IAC handout "Influenza Vaccination of People with a History of Egg Allergy" helpful (see www.immunize.org/catg.d/p3094.pdf).
Is allergy to chicken or duck feathers a contraindication to receipt of an egg-based influenza vaccine?
The influenza VIS states that giving pneumococcal conjugate vaccine and inactivated influenza vaccine simultaneously to young children may increase the risk of febrile seizures. Can we continue to give these two vaccines at the same time?
Yes, you can. Some, but not all studies, have reported increased rates of febrile seizures among children, especially those age 12 through 23 months, who received simultaneous vaccination with IIV and pneumococcal conjugate vaccine (PCV13, Pfizer) or DTaP vaccine (Daptacel, Infanrix, Pediarix, Pentacel), when compared with children who received these vaccines separately. However, because of the risks associated with delaying either of these vaccines, ACIP does not recommend administering them at separate visits or deviating from the recommended vaccine schedule in any way.
Febrile seizures, occurring in 2% to 5%, of all children, are not uncommon, and they are generally benign. Healthcare providers should be prepared to answer parents' questions about febrile seizures and fever when discussing vaccinations. Here is a helpful CDC resource: www.cdc.gov/vaccinesafety/Concerns/FebrileSeizures.html.
We usually instruct our patients that they should separate vaccinations and allergy shots by at least 24 hours because if there were a reaction to one or the other, it wouldn't be possible to determine which was the cause. This becomes problematic during influenza vaccination season. What should we do?
The probability of a serious allergic reaction following any vaccine is extremely low if the person is properly screened. ACIP has not issued a recommendation that desensitization injections and vaccines be separated by any specific time period; consequently, we feel that you should take the opportunity to vaccinate.
When I was 5 years old, I had Guillain-Barré syndrome (GBS) unrelated to vaccination. I am now 35 with no residual effects of the GBS. I am a nurse and my facility requires employees to receive influenza vaccine. Is it safe for me to be vaccinated?
Yes. A history of GBS unrelated to influenza vaccine is not a contraindication or precaution to influenza vaccination. GBS within 6 weeks following a previous dose of influenza vaccine is considered a precaution for use of influenza vaccines.
Administering Vaccines Back to top
Is there any plan to change the Influenza Vaccine Information Statement (VIS) for the 2020–21 influenza season?
Not at this time. Both the inactivated and the live influenza vaccine VISs (dated August 15, 2019) should be used for the 2020–21 influenza season.
Which formulations of influenza vaccines are licensed for various age groups?
Influenza vaccines differ with regard to age group indications. IAC has a handout that summarizes each of the products available for the current influenza vaccination season at www.immunize.org/catg.d/p4072.pdf. ACIP does not state a preference for one influenza vaccine over another for persons for whom more than one vaccine is recommended and is age- and health condition-appropriate.
When does CDC recommend starting influenza vaccination?
CDC recommends that vaccination should be offered by the end of October. Vaccination should continue throughout the influenza season, including into the spring months (for example, through May), as long as influenza viruses are circulating and providers have unexpired vaccine.
Children age 6 months to 8 years without two prior doses of influenza vaccine need 2 doses. They should get their first influenza vaccination as soon as vaccine becomes available to ensure they are fully vaccinated before the influenza season begins; the minimum interval for the second dose is 28 days.
To avoid missed opportunities for vaccination, providers should offer vaccination during routine healthcare visits and hospitalizations. However, for people who need only 1 dose, early vaccination (i.e., July and August) can result in reduced immune protection towards the end of the influenza season, particularly for older adults.
We are considering co-locating our COVID-19 drive-through testing site and influenza vaccination sites. Can we vaccinate someone with suspected or confirmed COVID-19 infection?
CDC recommends deferring vaccination for people with suspected or confirmed COVID-19 until they have met criteria for no longer needing quarantine or isolation to avoid exposing healthcare personnel and other patients. When scheduling or confirming appointments for vaccination, patients should be screened for COVID-19 symptoms and recent exposure.
Does ACIP prefer that healthcare professionals administer high-dose or adjuvanted influenza vaccine to people age 65 years and older, or is standard-dose influenza vaccine acceptable?
ACIP has no preference.
The pneumococcal conjugate vaccine (PCV13) package insert says that in adults, antibody responses to PCV13 were diminished when given with inactivated influenza vaccine. Does this mean we should not give PCV13 and influenza vaccine at the same visit?
The available data have been interpreted that any changes in antibody response to either of the vaccines' components were clinically insignificant. The antibody response was only lowered for three components, and ONLY in patients younger than 65 years of age. In this age group, if PCV13 is recommended, it means there is a high-risk of invasive pneumococcal disease for those unvaccinated. If PCV13 and influenza vaccine are both indicated and recommended, they should be administered at the same visit. See the PCV13 ACIP recommendations at www.cdc.gov/mmwr/pdf/wk/mm6337.pdf, page 824.
We have had three employees who have tested positive for influenza by nasal swab within 2 weeks of receiving Fluarix Quadrivalent (GlaxoSmithKline) vaccine. Is there a time period after receiving influenza vaccine that a nasal swab can give a false positive result?
Inactivated influenza vaccines, including Fluarix, are not known to cause false positive nasal swab tests. However, false positive test results are possible with rapid tests, and these are more likely to occur when influenza prevalence in the area is low. For more information regarding interpretation of rapid influenza tests see www.cdc.gov/flu/professionals/diagnosis/rapidlab.htm.
What is the preferred anatomic site for administration of inactivated influenza vaccine (IIV) and recombinant influenza vaccine?
IIV should be administered in the anterolateral thigh muscle of an infant or young child. IIV and RIV (approved for persons age 18 years and older) should be administered in the deltoid muscle of an older child, adolescent, or adult. The anterolateral thigh muscle can also be used for an older child, adolescent, or adult if necessary. It is critical that intramuscular influenza vaccine be injected into a muscle. Influenza vaccination season is an opportune time to review proper intramuscular injection techniques with your staff. IAC has prepared a handout on how to administer intramuscular vaccine injections (available at www.immunize.org/catg.d/p2020.pdf) that can be used as a staff training tool.
Some of our patients believe that they have had reactions to influenza vaccine in the past and request the dose to be split into 2 doses administered on different days. Is this an acceptable practice?
This is definitely not an acceptable practice. Doses of influenza vaccine (or any other vaccine) should never be split into "half doses." If a "half dose" is administered, it should not be accepted as a valid dose and should be repeated as soon as possible with a full age-appropriate dose.
Should staff at drive-through influenza vaccination clinics encourage drivers to park and wait for 15 minutes after vaccination to make sure they don't have a syncopal (fainting) episode?
Yes. Syncope has been reported following vaccination. It is prudent for all persons to be observed for syncope for at least 15 minutes after vaccination.
Is it acceptable to draw up vaccine into syringes at the beginning of the day? If it isn't, how much in advance can this be done?
CDC discourages the practice of prefilling vaccine into syringes for several reasons, including
the increased possibility of administration and dosing errors,
  the increased risk of inappropriate storage temperature,
  the probability of bacterial contamination since the syringe will not contain a bacteriostatic agent, and
the probability of reducing the vaccine's potency over time because of its interaction with the plastic syringe components.
Prefilling vaccine into syringes also violates basic medication administration guidelines, which state that an individual should administer only those medications he or she has prepared and drawn up.
Although pre-drawing vaccine is discouraged, a limited amount of vaccine may be pre-drawn in a mass-immunization clinic setting under the following conditions:
Only a single type of vaccine (for example, influenza) is administered at the mass-immunization clinic setting,
  vaccine is not drawn up in advance of its arrival at the mass-vaccination clinic site,
  these pre-drawn syringes are stored at temperatures appropriate for the vaccine they hold,
no more than 1 vial or 10 doses (whichever is greater) is drawn into syringes, and
  clinic staff monitor patient flow carefully and avoid drawing up unnecessary doses or delaying administration of pre-drawn doses.
At the end of the clinic day, any remaining vaccine in syringes prefilled by staff should be discarded.
Sometimes I am unable to get 10 doses of influenza vaccine out of a 5.0 mL (10-dose) vial. Do you have any suggestions?
Certain vaccine syringes have small hubs where a volume of the vaccine that is withdrawn from the vial collects and is not available to be injected. Syringes without a hub are available; their use results in less vaccine wastage.
When removing both pediatric (0.25 mL) and adult (0.5 mL) doses from a multi-dose vial of Fluzone Quadrivalent, we can get more than 10 doses from the 5.0 mL vial. Can we continue to remove doses from the vial until it is empty?
No. Only the number of doses indicated in the manufacturer's package insert should be withdrawn from the vial. For a 5.0 mL vial of Fluzone Quadrivalent this is 10 doses. For Afluria Quadrivalent 5.0 mL multi-dose vial, the package insert states that the stopper can be punctured up to 20 times, allowing up to 20 doses of 0.25 mL dose for children age 6–35 months old. After the maximum number of doses has been withdrawn or number of punctures of the stopper has met the FDA-recommended limit, the vial should be discarded, even if there is vaccine remaining in the vial and the expiration date has not been reached.
We inadvertently administered a 0.5 mL dose of Flucelvax (Seqirus) to a 2-year-old child before realizing that the vaccine is only licensed for use in people age 4 years and older. Do we need to repeat the dose with an age-appropriate product?
No, the dose does not need to be repeated. However, this is a vaccine administration error as this formulation is not recommended for children younger than age 4 years. Clinicians should carefully select an influenza vaccine that is licensed for the age group of the person being vaccinated. Currently Fluzone Quadrivalent 0.25 mL or 0.5 mL (Sanofi Pasteur), FluLaval Quadrivalent 0.5 mL (GSK), Fluarix Quadrivalent 0.5 mL (GSK), and Afluria Quadrivalent 0.25 mL (Seqirus) are the only inactivated influenza vaccines approved for use in children age 6 months through 35 months. Flumist (AstraZeneca) is approved for persons age 2 through 49 years.
If the child needs a second dose of influenza vaccine, an age-appropriate vaccine should be selected. IAC's educational piece "Influenza Vaccine Products for the 2020–21 Influenza Season" (available at www.immunize.org/catg.d/p4072.pdf) provides helpful information on the wide variety of influenza vaccines in use this season.
If the recombinant influenza vaccine (RIV4, Flublok Quadrivalent) was given inadvertently to a person younger than 18 years, can it be counted? Would there be any adverse side effects from this error?
Flublok Quadrivalent is not licensed for persons younger than 18 years of age, so there are no data regarding safety and efficacy in this age group. However, no serious side effects would be expected. The dose does not need to be repeated. Even if no adverse reaction occurs, we request that vaccine administration errors like this be reported to the Vaccine Adverse Events Reporting System at www.vaers.hhs.gov.
A 1-year-old was inadvertently given a 0.25 mL dose of FluLaval (or Fluarix) rather than the recommended 0.5 mL dose. What should we do?
If the error is discovered on the same clinic day you can administer the other "half" of the FluLaval Quadrivalent (or Fluarix Quadrivalent) dose. If the error is discovered the next day or later, the dose should not be counted. The child should be recalled to the office as soon as possible and given a full age-appropriate repeat dose, either a 0.5 mL dose of FluLaval Quadrivalent, a 0.5 mL dose of Fluarix Quadrivalent, a 0.25 or 0.5 mL dose of Fluzone Quadrivalent, or a 0.25 mL dose of Afluria Quadrivalent.
Storage and Handling  
How should influenza vaccines be stored?
All influenza vaccines (inactivated, recombinant, and live attenuated vaccines) should be stored at refrigerator temperature of 2° through 8°C (36° through 46°F). No influenza vaccine should be frozen. Influenza vaccine exposed to freezing temperature should not be used.
Back to top
This page was updated on October 22, 2020.
This page was reviewed on September 24, 2020.
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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. 6NH23IP22550) 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.