A report published as a preprint in medRxiv May 21st by Shapiro and others helps to evaluate this issue.
The authors used data from publication, reports, and press releases and concluded that the average efficacy of the Pfizer, Moderna, Johnson & Johnson, Oxford AstraZeneca, Sputnik, Novavax, Sinovac and Sinopharm vaccines was about 85% against any disease with infection.
Vaccine efficacy was greater than 80% for all vaccines included except for the Sinovac vaccine.
The average efficacy against severe disease, hospitalisation or death was nearly 100% and the average efficacy against infection, regardless of symptoms was 84%.
Additionally, this report found that the average vaccine efficacy against secondary transmission was 54%.
Average efficacy against the different SARS-CoV-2 variants was 86% for B117, 61% for B1128 or P1 and 56% for B1351.
Dr Paul Ettlinger
BM, DRCOG, FRCGP, FRIPH, DOccMed