World Health Organization, February 21,
2013
The recommended composition of influenza
virus trivalent vaccines for use in the 2013-2014 northern hemispheres (winter)
influenza season contain the following:
- A/California/7/2009 (H1N1) pdm09 like virus
- A(H3N2) virus antigenically like the cell propagated prototype virus A/Victoria/361/2011
- B/Massachusetts/2/2012-like virus
