Two new large, real-world studies yesterday in the New England Journal of Medicine (NEJM) show waning Pfizer/BioNTech COVID-19 vaccine protection, one finding dramatically lower protection against infection—but not hospitalization or death—5 to 7 months after the second dose in Qatar, and the other detailing reduced immune response over 6 months in Israel.Protection drops to 20% after 5 to 7 monthsA team led by Cornell University at Qatar researchers estimated vaccine effectiveness (VE) of the Pfizer vaccine against SARS-CoV-2 infection and severe or fatal disease from Jan 1 to Sep 5, 2021.
The observational study used a test-negative, case-control design.In Qatar, 947,035 of residents 12 years and older had received at least one Pfizer