This year’s flu vaccine has an effectiveness of 59%, according to estimates announced by the CDC. The figure was announced at a recent meeting of the CDC’s Advisory Committee for Immunization Practices (ACIP) in Atlanta, GA.

Since the CDC began estimating vaccine effectiveness in 2004-2005, records show the lowest level of effectiveness was for that season (10%), with the highest (60%) produced for the 2010-2011 season. Last season (2014-2015), the vaccine was only 23% effective.

This season’s preliminary 59% estimated vaccine effectiveness breaks down into more specific estimates for each of the following strains:

  • 51% effective against the H1N1 viruses responsible for most flu illness this season
  • 76% against all influenza B viruses
  • 79% against the B/Yamagata lineage of B viruses.