Recommended composition of influenza virus vaccines for use in the 2013-2014 northern hemisphere influenza season

Overview

21 February 2013

It is recommended that trivalent vaccines for use in the 2013-14 influenza season (northern hemisphere winter) contain the following:

• an A/California/7/2009 (H1N1)pdm09-like virus^a;
• an A(H3N2) virus antigenically like the cell-propagated prototype virus A/Victoria/361/2011^b*;
• a B/Massachusetts/2/2012-like virus.

It is recommended that quadrivalent vaccines containing two influenza B viruses contain the above three viruses and a B/Brisbane/60/2008-like virus^c.

^a A/Christchurch/16/2010 is an A/California/7/2009-like virus;
^b A/Texas/50/2012 is an A(H3N2) virus antigenically like the cell-propagated prototype virus A/Victoria/361/2011;
^c B/Brisbane/33/2008 is a B/Brisbane/60/2008-like virus.

* It is recommended that A/Texas/50/2012 is used as the A(H3N2) vaccine component because of antigenic changes in earlier A/Victoria/361/2011-like vaccine viruses (such as IVR-165) resulting from adaptation to propagation in eggs.