NEW YORK (AP) - U.S. health officials say the flu vaccine did a disappointing job last winter, and officials worry it might be a bad sign for the fall.
Flu vaccines for years were close to 60% effective against the flu strain that caused the most illnesses last winter, but it proved only 31% effective last season. Vaccines have already been only around 30% effective against another major type of flu.
Officials are worried the new results may be a sign of eroding effectiveness against a number of strains.
The findings were presented Wednesday during an over-the-internet meeting of an expert panel which the CDC looks to before making vaccination recommendations to U.S. doctors.