Flu Vaccines Expire on June 30th
Every year, the injectable inactivated influenza vaccine (IIV) has a standard expiration date of June 30 for the Northern Hemisphere influenza season.
This Centers for Disease Control and Prevention (CDC) statement on June 13, 2019, means ‘vaccination with an expired influenza vaccine might not protect against influenza infection because different influenza virus strains can be included in the vaccine each year.
The new year for flu vaccines starts on July 1st each year.
In addition, protection against the various influenza viruses included in the vaccine could wane if vaccine potency decreases over time.
The Vaccine Adverse Event Reporting System (VAERS) received 125 reports of patients receiving expired influenza vaccines during the 2018–19 influenza season.
During this time, there were a total of 169.1 million doses of seasonal influenza vaccine distributed in the USA.
Adverse events after the administration of an expired IIV were rarely reported, 4 of 125 reports; 3.2%.
The VAERS adverse event findings suggest that expired IIV does not pose additional risks for adverse events beyond those of seasonal IIV.
In most VAERS reports, factors that contributed to the administration of expired vaccine were not specified. However, seven reports detailed that patients were offered revaccination with the current season’s influenza vaccine; of these, three confirmed revaccinations.
As a spontaneous reporting surveillance system, VAERS likely captures only a small fraction of expired IIV administered; therefore, this error might be more common than VAERS data indicate.
Recent VAERS news:
The CDC’s Vaccine Storage and Handling Toolkit contains guidance pertaining to the prevention of and mitigation of administration of expired vaccines and is available online.
This guidance includes:
- Vaccine stock should be rotated and examined for expired doses regularly.
- Any expired vaccines and diluents should be removed immediately to avoid inadvertent administration.
- Vaccines should be inspected for expiration before they are administered or transported to other facilities.
- Facility vaccine coordinators need to be aware of the standard expiration date of June 30 for IIV and make plans for the safe disposal or return of any remaining doses of IIV after that date.
Most importantly, the CDC says any person who receives an expired influenza vaccine should be revaccinated with the current season’s influenza vaccine.