How effective are Flu Shots? CDC says its an (optimistic) 40%
The CDC website posts information for each of the last 14 flu seasons on the effectiveness of each year’s flu vaccine. Averaged out, the effectiveness of flu vaccines is 40.5%. Figure. Effectiveness of Seasonal Flu Vaccines from the 2004-2018 Flu Seasons While that may not sound too bad, it means that 60% or 3 out of every…