Since health officials started tracking it in 2003, effectiveness of the flu shot has varied from year to year, averaging at 40%.
Source: https://www.webmd.com/lung/news/20200902/how-effective-is-the-flu-vaccine?src=RSS_PUBLIC
Since health officials started tracking it in 2003, effectiveness of the flu shot has varied from year to year, averaging at 40%.
Source: https://www.webmd.com/lung/news/20200902/how-effective-is-the-flu-vaccine?src=RSS_PUBLIC