AS SWINE flu’s death toll rises, so does demand for a vaccine. The trouble is, the strains produced so far are growing half as fast as ordinary vaccine strains, which means they may not be ready in time for the flu’s next wave.
Vaccine companies are obliged to first fill existing pandemic vaccine contracts with countries such as the UK, Australia and France. Only then can they make vaccine for everyone else.
How quickly vaccine can be made depends on how fast vaccine strains grow and how much is needed. The World Health Organization that existing contracts can be filled as early as November 2009 if people need only one shot of half the ordinary vaccine dose, and by April 2010 if two shots of the usual dose is needed. However, this assumes that the strain grows at the same rate as ordinary flu.
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According to another presented by the WHO last week, of five different vaccine strains produced so far, the two fastest growing only grow half as fast as those used to make ordinary flu vaccine. This could push the dates back to January and June 2010, respectively, by which time the virus’s next, possibly worse, wave may be over.