Pfizer-BioNTech Vaccine

The Pfizer-BioNTech vaccine showed 80% efficacy against infection with the Delta variant. Efficacy against hospitalization decreased to 70% with the Omicron variant, still constituting strong protection. Vaccine efficacy against hospitalization was 93% with the Delta variant. Vaccine efficacy against infection dropped significantly to 33% against the Omicron variant. The efficacy figures in the article are based on a two-dose vaccination series. A three-dose regimen of the Pfizer-BioNTech vaccine would likely yield higher efficacy numbers for both infection and hospitalization prevention.