– an A/Brisbane/59/2007 (H1N1)-like virus;*
– an A/Brisbane/10/2007 (H3N2)-like virus;**
– a B/Florida/4/2006-like virus.***
*A/South Dakota/6/2007 (an A/Brisbane/59/2007-like virus) is a current vaccine virus used in live attenuated vaccines.
**A/Brisbane/10/2007 and A/Uruguay/716/2007 (an A/Brisbane/10/2007-like virus) are current vaccine viruses.
***B/Florida/4/2006 and B/Brisbane/3/2007 (a B/Florida/4/2006-like virus) are current vaccine viruses.
Background: Twice annually, the WHO Global Influenza Programme analyses the global data on circulating influenza strains and issues recommendations on the formulation of the influenza vaccine for the following influenza season. These recommendations are used by the national drug licensing agencies and the pharmaceutical companies to update the content of the influenza vaccines they produce. An annual adjustment of the vaccine content is necessary to match the vaccine with the ever changing antigenic and genetic characteristics of circulating influenza viruses.
The influenza vaccine composition to be used in the 2008-2009 influenza season in the U.S. is identical to that recommended by the World Health Organization on 14 Feb 2008 for the Northern Hemisphere’s 2008-2009.
In summary, perhaps unusually, the composition of the influenza vaccines for use in the northern and southern hemispheres in 2009 are identical.