mRNA COVID vaccines highly effective against Delta hospitalization, deathTwo doses of the Pfizer/BioNTech and Moderna mRNA COVID-19 vaccines were 93% and 96% effective, respectively, in preventing severe, critical, or fatal disease caused by the highly transmissible Delta (B1617.2) variant, a study today in Nature Medicine finds.Researchers in Qatar evaluated the vaccines' effectiveness in residents from Mar 23 to Sep 7, 2021, a period in which 43% of COVID-19 cases were attributed to Delta.
Over 80% of Qataris were estimated to have been fully vaccinated by Sep 19.During the study period, 88 and 1,126 Delta breakthrough infections and 4 and 15 cases requiring hospitalization occurred among residents vaccinated with one or two Pfizer