The effectiveness of Pfizer’s Covid-19 vaccine declines over time, dropping to about 84% for vaccinated people about four to six months after getting their second dose, according to CEO Albert Bourla in an interview with CNBC.
The comments, made Wednesday, are based on the findings of a new company-funded study that has yet to be peer reviewed. It comes as the drug firm clashes with U.S. health officials over the possibility of the need of a third Covid vaccine dose to boost immunity protection.
The study found the vaccine’s effectiveness was strongest, at 96.2%, between one week and two months after receiving the second dose. It declined an average of 6% every two months. The efficacy after “four to six months was approximately 84%,” Bourla said.