Just one dose of the BioNTech/Pfizer, Moderna or Oxford/AstraZeneca vaccines offers higher protection against symptomatic illness caused by the Delta variant than previous studies have shown, a Canadian study has reported.
The real world study, which isn’t yet peer reviewed, was announced by AstraZeneca Friday but first published on July 16. It compared the efficacy of the BioNTech/Pfizer, Moderna and Oxford/AstraZeneca vaccines against several variants of concern. The authors found that even a single dose of any of the three vaccines provides “considerable protection against symptomatic infection and severe outcomes.”
In particular, protection against the Delta variant, first identified in India, was 56 percent effective against symptomatic infection after one dose of the BioNTech/Pfizer vaccine. Moderna was 72 percent effective, and Oxford/AstraZeneca 67 percent.
As for more severe illness resulting in hospitalization or death, the Canadian study indicated that one dose of the BioNTech/Pfizer, Moderna and Oxford/AstraZeneca vaccines was 78 percent, 96 percent and 88 percent effective, respectively, against the Delta variant.