Ask the Experts: Influenza: Administering Vaccines

Results (14)

Both the inactivated and recombinant influenza vaccine VIS and the live influenza vaccine VIS were updated on August 6, 2021. These VISs and translations in multiple languages are available here: www.immunize.org/vis/.

Last reviewed: September 10, 2023

Immunize.org has a 1-page printable document that summarizes each of the products available for the current influenza vaccination season, including age indications, at www.immunize.org/catg.d/p4072.pdf.

Last reviewed: September 10, 2023

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
  • The probability of reducing the vaccine’s potency over time

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
  • 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, all remaining vaccine in syringes prefilled by staff should be discarded.

Last reviewed: September 10, 2023

Vaccinating people against influenza who have recently tested positive for COVID-19 involves multiple considerations, such as whether vaccinating them could expose others to COVID-19, how sick they are, their risk for severe influenza illness, the ability to vaccinate at a later date, and the desire to avoid confusing postvaccination symptoms with those of COVID-19. Usually, people who are infectious should not be brought to a vaccination setting if doing so could expose others to COVID-19. Any moderate or severe acute illness is a precaution to influenza vaccination: vaccination should generally be deferred until recovery. For people with mild or asymptomatic COVID-19, delaying vaccination might be considered to avoid confusing COVID-19 symptoms with postvaccination reactions.

CDC may continue to modify recommendations for vaccination of this population.

Last reviewed: September 10, 2023

Inactivated influenza vaccines are not known to cause false positive nasal swab tests. The results may indicate real infections; however, false positive test results are possible with rapid tests, and these are more likely to occur if the tests are done 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.

Last reviewed: September 10, 2023

IIV should be administered in the anterolateral thigh muscle of an infant or young child. IIV and RIV (approved for people 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. Immunize.org has prepared a printable document 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.

Last reviewed: September 10, 2023

This is 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. The second half of the dose may be administered if the error is caught and corrected at that visit; if not, repeat the vaccination as soon as possible with a full age-appropriate dose.

Last reviewed: September 10, 2023

Yes. Syncope may occur following any vaccination. It is prudent for all people to be observed for syncope for at least 15 minutes after any vaccination.

Last reviewed: September 10, 2023

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.

Last reviewed: September 10, 2023

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.

Last reviewed: September 10, 2023

The dose does not need to be repeated. However, this is a vaccine administration error. Clinicians should carefully select an influenza vaccine and vaccine dose that is licensed for the age group of the person being vaccinated. The error should be conveyed to the child’s parent or guardian and also reported to Vaccine Adverse Events Reporting System (VAERS) at www.vaers.hhs.gov. Actions should be taken to limit vaccine administration errors at the clinic where the error occurred. Immunize.org’s educational piece “Influenza Vaccine Products for the 2023-24 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.

Last reviewed: September 10, 2023

RIV4 is not licensed for people 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, vaccine administration errors like this should be reported to the Vaccine Adverse Events Reporting System (VAERS) at www.vaers.hhs.gov.

Last reviewed: September 10, 2023

If the error is discovered on the same clinic day you can administer the other “half” of the FluLaval 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, a 0.25 mL dose of Afluria Quadrivalent, or a 0.5 mL dose of Flucelvax Quadrivalent.

Last reviewed: September 10, 2023

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