Pfizer Vaccine Is 90% Effective 3 Weeks After First Shot, Early Study Shows
WEDNESDAY, Feb. 3, 2021 (HealthDay News) — Just one dose of Pfizer’s coronavirus vaccine might be enough to largely protect people from being infected with COVID-19, preliminary research shows. The vaccine became 90% effective 21 days after the first shot in a two-dose regimen, said British researchers who looked atContinue Reading










