WHO | Recommended composition of influenza virus vaccines for use in the 2013-14 northern hemisphere
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 ant...