The WHO released “Recommended viruses for influenza vaccines for use in the 2010-2011 northern hemisphere influenza season, February 2010.” WHO noted that it “convenes technical meetings1 in February and September each year to recommend viruses for inclusion in influenza vaccines for the northern and southern hemispheres, respectively. This recommendation relates to the influenza vaccines for the forthcoming influenza season in the northern hemisphere (2010 – 2011). A recommendation will be made in September 2010 relating to vaccines that will be used for the influenza season in the southern hemisphere (2011). For countries in equatorial regions epidemiological considerations will influence which recommendation (February or September) individual national and regional authorities consider more appropriate.”

“…Based on the analyses it is expected that A(H1N1) pandemic 2009, A(H3N2) and B viruses will co-circulate in the northern hemisphere 2010-2011 with the likelihood that the pandemic A(H1N1) 2009 viruses will predominate. Based on recent epidemiological evidence it is anticipated that seasonal A(H1N1) viruses are unlikely to circulate at significant levels during the 2010-2011 northern hemisphere season; hence it has not been recommended for inclusion in the 2010-2011 vaccine. A B/Victoria/2/87 lineage virus, the predominant lineage of type B viruses circulating since September 2009, has been recommended.

“It is recommended that the following viruses be used for influenza vaccines in the 2010- 2011 influenza season (northern hemisphere):

– an A/California/7/2009 (H1N1)-like virus;

– an A/Perth/16/2009 (H3N2)-like virus;#

– a B/Brisbane/60/2008-like virus.

# A/Wisconsin/15/2009 is an A/Perth/16/2009 (H3N2)-like virus and is a 2010 southern hemisphere vaccine virus…

http://www.who.int/csr/disease/influenza/201002_Recommendation.pdf