WHO recommends that for the 2010-2011 influenza season, the following viruses be included in influenza vaccines:
- An A/California/7/2009 (H1N1)-like virus
- An A/Perth/16/2009 (H3N2)-like virus
- A B/Brisbane/60/2008-like virus
Trivalent vaccines that contain all three of the WHO recommended viruses are expected to protect against both pandemic and seasonal influenza.
Source: WHO http://www.who.int/csr/disease/influenza/201002_RecommendationFAQ.pdf