TEL AVIV – A single injection of the Covid-19 vaccine developed by Pfizer Inc. and BioNTech SE is 85% effective in preventing symptomatic diseases 15 to 28 days after administration, concluded an Israeli study, a development that may help guide the definition priority vaccine policy makers around the world.
Some governments are debating whether to delay the second injection of the recommended two-dose regimen to make the most of the lack of vaccines.
The Israeli study, conducted by the Sheba Medical Center and released on Friday, also found a 75% reduction in all Covid-19 infections, symptomatic or asymptomatic, after the first injection. The peer-reviewed study was published in the British medical journal Lancet as a correspondence, which means that it represents the opinions of the authors and not the journal.
The data used were collected from the 9,109 health workers at the center, who started the vaccination process from December 19.
“This is the first study evaluating the efficacy of a single dose of vaccine in real-life conditions and shows early efficacy, even before the second dose is administered,” said Prof. Eyal Leshem, director of the Sheba Center for Travel Medicine and Tropical Diseases of the study authors.