# 2649
At a time when public health officials are extolling the virtues of getting a yearly flu shot, this isn't the kind of news they want to hear. Particularly after last year's poor vaccine performance.
Early indications are that the Influenza B component of this years' shot may not be a good match for the Influenza B in circulation.
The good news, at least in the United States and Europe, is that the H1N1 and H3N2 components of the vaccine appear to be good matches, and (so far) those two strains are the major players in those regions.
In Canada, however, influenza B is emerging as the dominate flu strain, and a mismatch in the `B' component of the vaccine becomes a bigger deal for them.
`Selling' the idea of yearly flu shots isn't easy, particularly when so many people lament that `I got a flu shot last year, and still got the flu!'.
Flu shots aren't perfect of course, and sometimes scientists guess wrong about what flu strains will be circulating six months in the future. In addition, there are many influenza-like-illnesses (ILI's) that simply aren't covered by the flu vaccine.
Adenovirus, rhinovirus, Respiratory syncytial viruses A and B; and the parainfluenza viruses are just some of the culprits that can take you down, and make you miserable, but aren't `influenza'.
Despite the known benefits to getting a flu shot, no one remembers the flu they didn't catch - the one prevented by a flu shot - they only remember the illnesses that the shot didn't prevent.
Trying to explain that it wasn't really the `flu', and therefore not supposed to be covered by their flu shot, doesn't tend to win friends or influence them to get a shot every year.
Helen Branswell, of the Canadian Press, brings us the latest on what is looking like at least a partial miss this year on the `B' component of the flu vaccine, and the idea of adding a second `B' component to the flu shot.
Flu shot mismatched on B virus; experts study adding extra strain to vaccine
Provided by: Canadian Press
Written by: Helen Branswell, THE CANADIAN PRESS
Jan. 11, 2009
TORONTO - 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.
