Every spring, federal health officials select two influenza A virus strains (usually H1N1 and H3N2 subtypes)23 and one or two influenza B virus strains24 to include in flu vaccines released in the fall. This past December, CDC officials held a press conference and informed Americans that they were unaware last spring that one of the influenza A strains selected for the 2014-2015 flu vaccine – the H3N2 subtype – was starting to “drift.” It turns out that the genetically mutated subtype is the dominant influenza A strain causing sickness this year, but it is not in the flu vaccine.
Flu Vaccine Effectiveness Measured from 0 to 62 Percent In the past three flu seasons, the CDC has claimed the flu vaccine’s overall effectiveness clocked in at between 47 and 62 percent3 while some experts have measured it at 0 to 7 percent. Other studies suggest that when children get a flu shot every year it…
