Tuesday, January 13, 2009

Flu shot mismatched on B virus

From the Toronto Star:
It appears there may be a partial flu shot mismatch again this year, with early data from Canada, the United States and Britain suggesting the vaccine component meant to protect against influenza B is not a match for the flu B viruses causing the most disease.

Predicting which family of influenza B viruses will dominate in a coming year – and therefore should be covered by the flu shot – is a challenge that has defied the experts in five of the last seven flu seasons, at least so far as disease patterns in North America are concerned.

The ongoing problem has prompted exploration of the idea that flu shots should be reformulated to add a second B component to a vaccine that currently protects against one family of B viruses and the two influenza A subtypes, H3N2 and H1N1.

Scientists from the U.S. Centers of Disease Control are working on a cost-benefit analysis of just such a move and are to meet Monday to begin going over the pros and cons. They plan to present their findings sometime next month to the Food and Drug Administration, which regulates vaccines in the United States.

"Historically it's obviously been difficult to predict which one's coming next," Dr. Joseph Bresee, the CDC's chief of influenza surveillance and prevention, says of the flu B viruses. ...more

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