June 4, 2015
Flu shot only 19% effective this winter
Flu vaccines were only 19% effective in preventing doctor visits for influenza this season, one of the lowest rates in the past decade, the Centers for Disease Control and Prevention said Thursday. Health officials had predicted flu shots would be less protective than usual this year. That's because the viruses used to make the flu shots weren't a good match for the dominant strains of influenza in circulation, said Brendan Flannery, an epidemiologist in the CDC's influenza division.