Pfizer-BioNTech COVID-19 vaccine

The Moderna and Pfizer-BioNTech vaccines were about 95 percent effective in preventing infection with SARS-CoV-2; the Janssen vaccine was about 67 percent effective in preventing moderate to severe disease. Other vaccines included the Oxford-AstraZeneca COVID-19 vaccine, a recombinant vaccine first approved in the United Kingdom in late 2020,…

…SARS-CoV-2, scientists at Moderna and Pfizer-BioNTech had experimental mRNA vaccines ready for testing.