Recommended composition of influenza virus vaccines for use in the 2008 influenza season.

This recommendation relates to the composition of vaccines for the forthcoming winter in the southern hemisphere (May–October 2008). A recommendation will be made in February 2008 relating to vaccines that will be used for winter in the northern hemisphere (November 2008–April 2009). Epidemiological considerations will influence which recommendation (September 2007 or February 2008) is more appropriate for countries in equatorial regions.