Each year vaccine makers create a cocktail of antigens designed to stand guard against the various versions of the flu making the rounds in winter. But this year the CDC concludes that most of the influenza B viruses in the U.S. aren't being stopped by the vaccine. Two of the three components in the vaccine aren't aimed the right B targets, it seems. The jab may, though, offer protection against the A versions in circulation.
"Most years, the prediction is very good," Joseph Bresee, an influenza epidemiologist at the CDC, tells the Washington Post. "In 16 of the last 19 years, we have had a well-matched vaccine."
- read the report from the Wall Street Journal