Israeli study finds Pfizer vaccine 85% effective after first shot

JERUSALEM (Reuters) – First dose of Pfizer Inc.’s COVID-19 vaccine is 85% effective, according to study of healthcare workers at an Israeli hospital, potentially fueling debate over recommended two-dose schedule as governments try to expand supplies.

Sheba Medical Center’s results compare with an overall efficacy of around 95% in a two-dose regimen 21 days apart for the vaccine developed with BioNTech in Germany.

The Sheba study, which will be published in the medical journal The Lancet, comes a day after Canadian researchers suggested that the second dose of Pfizer be delayed due to the high level of protection on the first shot in order to increase the number people getting vaccinated.

Their research showed 92.6% effectiveness after the first dose, based on a review of documents submitted by the drug maker from its advanced human trials to the U.S. Food and Drug Administration in December. .

The FDA said in December that data from those trials showed the vaccine had started to provide some protection to recipients before they received the second vaccine, but that more data would be needed to assess a vaccine’s potential. single dose.

Pfizer said alternative vaccine dosing schedules have yet to be evaluated and the decision rests with health officials.

Sheba said that among 7,214 hospital staff 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 epidemiologist Gili Regev-Yochay warned that the cohort studied at the hospital was “mostly young and healthy”.

Unlike the Pfizer clinical trial, “we don’t have a lot of (staff) here over the age of 65,” she told reporters. But she also noted that the Sheba study took place during an outbreak of COVID-19 infections in Israel, which inundated hospitals with new cases.

Pfizer declined to comment on the data, saying in a statement it was conducting its own analysis of “the actual effectiveness of the vaccine in several parts of the world, including Israel.” He hopes to use Israeli data to examine the vaccine’s potential to protect against COVID-19 resulting from emerging variants, the drugmaker said.