With Vaccine Mismatch, a Tough Flu Season

This flu season was the worst in four years, U.S. health officials say. One major reason, they say, is that the flu vaccine did not protect well against the two most common strains causing illness this year. Overall, the vaccine was about 44% effective. Usually, it is 70% to 90% effective. The Associated Press reported April 17 on the new statistics. The study was conducted by the U.S. Centers for Disease Control and Prevention. It was published in the centers’ Morbidity and Mortality Weekly Report.