Pfizer Says Vaccine's Power Wanes Over Time. Are You Still Protected?
New research from Pfizer found a drop in protection after six months, although the vaccine remained highly effective against severe illness
Published July 28, 2021
NBCUniversal Media, LLC
The effectiveness of the Pfizer-BioNTech COVID-19 vaccine waned over six months, but experts say the data still don't point to an immediate need for booster shots.
The study, which hasn't yet been peer-reviewed or published in a medical journal, found that the vaccine was 97 percent effective at preventing severe disease from COVID-19 for at least six months — but the effectiveness against any symptomatic illness dropped from 96 percent to 84 percent in the same period, falling by about 6 percent every two months.