Expired Live Attenuated Influenza Vaccine Being Administered
Written by Brooke Shaw   
Thursday, October 16, 2014 01:35 PM

Nearly 20% or more of intranasally administered influenza vaccination may be expired.

A recent report notes that "annual influenza vaccination is recommended for all persons aged ≥6 months. Two vaccine types are approved in the United States, injectable inactivated influenza vaccine (IIV) and live attenuated influenza vaccine (LAIV), which is administered intranasally." 

"Influenza vaccine typicaly becomes widely available beginning in late summer or early fall. IIV has a standard expiration date of June 30 for any given influenza season (July 1 through June 30 of the following year)."

"In contrast, after release for distribution, LAIV generally has an 18-week shelf life .... Because of its relatively short shelf life, LAIV might be more likely than IIV to be administered after its expiration date. To assess that hypothesis, CDC analyzed reports to the Vaccine Adverse Event Reporting System (VAERS) of expired LAIV administered during July 1, 2007, through June 30, 2014."

"Of the 4,699 LAIV reports, 866 (18.4%) involved administration of expired vaccine."

"As a passive surveillance system, VAERS likely captures only a small fraction of expired LAIV administered, so this error might be more common than VAERS data indicate."

Source:  http://www.medscape.com/viewarticle/831182?src=wnl_edit_specol&uac=151914AX