Euro studies show flu vaccine working best against type B

New European studies, reported in Eurosurveillance, suggest that this year’s  influenza vaccine is providing good protection against influenza B viruses but only moderate protection against type A—findings more or less consistent with earlier results in the United States. In a study combining data from five countries, vaccine effectiveness (VE) against influenza B was estimated at about 78%, versus about 62% and 42% for the two influenza A strains. Overall protection was estimated at about 62%. In Navarre, Spain, where type B viruses have been predominant this season, overall VE was estimated at 86%, according to another report. Both studies suggest parallels with a January VE estimate from the US Centers for Disease Control and Prevention (CDC). The CDC’s early-season estimate for the United States was that the vaccine was 70% effective against type B, 55% against type A, and 62% overall. The overall estimate was in line with a recent meta-analysis of controlled...