The World Health Organization is recommending that the H1N1 swine flu strain be added to next year's seasonal flu vaccine in the northern hemisphere. That will likely mean that most Canadians need only one flu shot next fall.
The WHO held a meeting this week to decide which influenza strains should be recommended to northern hemisphere drug makers for their vaccines.
The vaccines typically contains protection against three virus strains: two influenza A strains and one influenza B. Experts decide on those strains after monitoring flu activity around the world, looking for the most common strains that are making people sick.
Last year, the swine flu virus, or H1N1, emerged too late to be added to the regular flu vaccine and a new vaccine was needed.
The WHO said in a statement Thursday that for the 2010/11 season, it recommends that H1N1 swine flu be added to the vaccine (the strain is technically named A/California/7/2009), and as well as a strain of H3N2 called Perth/16/2009, and B/Brisbane/60/2008.
"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," the WHO said in the statement.
It added that other seasonal H1N1 viruses were "unlikely to circulate at significant levels during the 2010-2011 northern hemisphere season; hence it has not been recommended for inclusion."
The composition of the southern hemisphere's separate seasonal vaccine for 2010 was announced last September; it also contains the H1N1 pandemic strain.
The recommendation, announced at the end of a four-day closed-door meeting of influenza experts, could mean that governments that have stockpiled doses of H1N1 vaccine may now use them for part of the seasonal flu vaccine mix.
"If they have the vaccine strain which is already made up and can be used, then they're ahead of the game," Keiji Fukuda, the WHO's top influenza expert, told Reuters after a public WHO session.
Canada bought 50.6 million doses of H1N1 vaccine, the bulk of which was made by GlaxoSmithKline. The large order was placed at a time when it was thought two doses per person might be needed.
The federal government donated five million doses to the World Health Organization late last month. But it's estimated that it still has a surplus in the neighbourhood of 30 million doses.
Also on Thursday, Fukuda said the WHO's emergency committee of experts will meet on Feb. 23 to decide whether the H1N1 flu pandemic has peaked.
