Swine flu virus should be in next year's seasonal flu vaccine
The pandemic H1N1 influenza virus should be a component of the seasonal flu vaccine prepared for the coming winter in the Southern Hemisphere and probably in next year's vaccine for the Northern Hemisphere as well, the World Health Organization said today.
The virus, commonly known as swine flu, has become the predominant circulating type A influenza virus, and the seasonal flu vaccine should reflect that, the agency said. The practical impact will be that only one flu shot will be required once the world makes it through this fall's round of dual injections for swine and seasonal flu.
The swine flu virus was not included in this winter's seasonal shot because it made its debut on the world stage after manufacturers had already begun working on the seasonal vaccine. That meant that pharmaceutical companies had to go through a second round of production for the swine flu after they had finished producing their regular batches of seasonal vaccine. At least 2 billion doses of swine flu vaccine are expected to be produced this fall.
Manufacturers will not begin working on the new vaccine for several months, so they will be able to choose a slightly different strain of the virus if it begins, as many people suspect it eventually will, to show some antigenic drift.
If the WHO recommendation is solidified at an advisory committee meeting next month, the seasonal vaccine will contain not only the pandemic H1N1 virus but also an H3N2 strain isolated in Perth and an influenza B virus isolated in Brisbane.
-- Thomas H. Maugh II