Seasonal Flu Shot May Boost H1N1 Risk

The WHO has asked researchers around the world if their findings back up a Canadian study that shows people who received seasonal flu vaccines are more likely to contract swine flu. So far, the results haven't been repeated. “None have been able to find anything like that,” the WHO’s head of vaccine research told CTV. “The plausibility seems sort of in question. It may be study bias; it may be something real.”

Health officials in many Canadian provinces are considering suspending their flu vaccination programs. Few have seen the study, which is still under peer review, but the findings appear to suggest that those who got flu shots last year were twice as likely to get H1N1 this year. The study's lead author urges reserving judgment until after the peer review is complete, saying, “Good scientists know that methods can influence results.” (More H1N1 virus stories.)