A CDC advisory committee voted yesterday to recommend against use of MedImmune’s FluMist® Quadrivalent live attenuated influenza vaccine (LAIV)—also known as the “nasal spray” flu vaccine—during the 2016–2017 flu season.
CDC’s Advisory Committee on Immunization Practices (ACIP) did, however, continue to recommend annual flu vaccination, with either the inactivated influenza vaccine (IIV) or recombinant influenza vaccine (RIV), for all people 6 months old and older.
CDC said the vote of the ACIP, which includes immunization experts, was based on data showing poor or relatively lower effectiveness of LAIV from 2013 through 2016. ACIP recommendations are subject to final review and approval by CDC Director Thomas R. Frieden, M.D., M.P.H.
The agency cited preliminary data on the effectiveness of LAIV among children ages 2–17 years during the 2015–2016 season, which became available from the U.S. Influenza Vaccine Effectiveness Network. That data, according to CDC, showed the estimate for LAIV vaccine effectiveness (VE) among study participants in that age group against any flu virus was 3%—effectively meaning that no protective benefit could be measured.
By comparison, IIV (flu shots) had a VE estimate of 63% against any flu virus among children ages 2–17. Other (non-CDC) studies support the conclusion that LAIV worked less well than IIV this season. The data from 2015–2016 followed two previous seasons that showed poor and/or lower than expected VE for LAIV, CDC said.
CDC said MedImmune, a subsidiary of AstraZeneca, had projected a supply of up to 14 million doses of LAIV/nasal spray flu vaccine, or about 8% of the total projected supply of all forms of flu vaccine available in the U.S. for the upcoming season. That projected supply ranges from 171–176 million doses.
In a statement today, AstraZeneca said the CDC’s data contrasted with studies by the company and preliminary independent findings by public health authorities in other countries.
“These findings demonstrate FluMist Quadrivalent was 46–58% effective overall against the circulating influenza strains during the 2015–2016 season,” the company stated. “AstraZeneca is working with the CDC to better understand its data to help ensure eligible patients continue to receive the vaccine in future seasons in the U.S.”
Distribution and use of the vaccine in other countries are progressing as planned for the forthcoming influenza season, AsraZeneca added.
LAIV was initially approved by the FDA in 2003 as a trivalent vaccine and is available both in trivalent and quadrivalent forms.
FluMist Quadrivalent, approved by the FDA in 2012, is indicated for active immunization for the prevention of influenza disease caused by influenza A subtype viruses and type B viruses contained in the vaccine, and is approved for users ages 2–49. According to AstraZeneca, FluMist Quadrivalent generated $206 million in U.S. product sales last year.
“The ACIP’s updated recommendation is expected to result in very limited U.S. demand in the second half of 2016 and consequently the company will take an inventory write-down of approximately $80 million in the second quarter of 2016,” AstraZeneca stated.
However, the company maintains its overall 2016 financial guidance. AstraZeneca has told investors it anticipates “low- to mid- single-digit percentage” declines in both total revenue and core earnings per share.