JERUSALEM (Reuters) – Pfizer Inc’s first dose of COVID-19 vaccine is 85% effective, a study of healthcare workers at an Israeli hospital found, potentially fueling a debate over the recommended schedule of two doses as governments try to stretch supplies.
The Sheba Medical Center findings compare with an overall efficacy of around 95% on a two-dose regimen 21 days apart for the injection developed with BioNTech from Germany.
The Sheba study, to be published in The Lancet medical journal, comes a day after Canadian researchers suggested that the second dose of Pfizer be delayed given the high level of protection from the first injection to increase the number of people taking it. vaccinate.
Their research showed an efficacy of 92.6% after the first dose, according to an analysis of documents submitted by the drug manufacturer from its late-stage human trials to the US Food and Drug Administration.
The FDA said in December that data from those trials showed the vaccine began to confer some protection on recipients before they received the second injection, but more data would be needed to assess the potential of a single-dose injection.
Pfizer has said that alternative dosing regimens for the vaccine have yet to be evaluated and that the decision rests with health authorities.
Sheba said that among 7,214 hospital employees who received their first dose in January, there was an 85% reduction in symptomatic COVID-19 within 15 to 28 days. The overall reduction in infections, including asymptomatic cases detected by testing, was 75%.
Sheba’s epidemiologist, Gili Regev-Yochay, cautioned that the cohort studied at the hospital was “mostly young and healthy.”
Unlike the Pfizer clinical trial, “we don’t have many (employees) here over the age of 65,” he told reporters. But he also noted that Sheba’s study was carried out during a surge in COVID-19 infections in Israel, flooding hospitals with new cases.
Pfizer declined to comment on the data and said in a statement that it was doing its own analysis of “the vaccine’s effectiveness in the real world in various locations around the world, including Israel.” It hopes to use Israeli data to analyze the vaccine’s potential to protect against COVID-19 arising from emerging variants, the drugmaker said.
Written by Dan Williams; Edited by Jane Merriman