Observational study in Qatar showed the effectiveness of Pfizer vaccine against any SARS-CoV-2 infection dropped to 20% in months 5 through 7 after the second dose, but effectiveness against severe Covid-19 remained high.
7 Oct, 2021 | 10:55h | UTC
Commentary on Twitter
In this 900,000-participant study in Qatar, vaccine effectiveness peaked at 77.5% in the first month after the second dose. The effectiveness fell to as low as 20% in months 5 through 7 after vaccination. #Covid19vaccine #IDTwttier https://t.co/TeDcLLftIH pic.twitter.com/pEBoxs6Hmr
— NEJM (@NEJM) October 6, 2021