Pfizer vaccine 85% effective after first shot, Israeli study finds


Pfizer said alternative dosing regimens of the vaccine have not yet been evaluated


Pfizer Inc.’s first dose of COVID-19 vaccine is 85 percent effective. This was found in a study by health care workers at an Israeli hospital that may spark a debate about the recommended two-dose schedule if governments try to expand care.

The results of the Sheba Medical Center are comparable with an overall effectiveness of around 95% in a two-dose regimen at intervals of 21 days for the shot developed with Germany’s BioNTech.

The Sheba study, due to be published in The Lancet Medical Journal, appears a day after Canadian researchers suggested delaying the second dose of Pfizer before the first shot due to the high level of protection in order to increase the number of people vaccinated.

Their research showed 92.6 percent effectiveness after the first dose, based on an analysis of the documents the drug maker submitted to the U.S. Food and Drug Administration in December from its late human studies.

The FDA said in December that data from these studies showed that the vaccine gave recipients some protection before they received the second shot. However, more data would be needed to assess the potential of a single dose shot.

Pfizer said that alternative dosing regimens of the vaccine have not yet been evaluated and that the decision was up to health officials.


Sheba said there was an 85% reduction in symptomatic COVID-19 in 15 to 28 days among 7,214 hospital workers who received their first dose in January. The overall reduction in infections, including asymptomatic cases identified by testing, was 75%.

Sheba epidemiologist Gili Regev-Yochay warned that the cohort studied in the hospital was “mostly young and healthy.”

Unlike the Pfizer clinical study, “we don’t have many (employees) over 65 years of age here,” she told reporters. But she also noted that the Sheba study happened during a surge in COVID-19 infections in Israel that was flooding hospitals with new cases.

Pfizer declined to comment on the data, saying in a statement that it was conducting its own analysis of “the real effectiveness of the vaccine in several locations worldwide, including Israel”. She hopes to use Israeli data to examine the vaccine’s potential to protect against COVID-19 arising from emerging variants, the drug maker said.

(This story was not edited by GossipMantri staff and is automatically generated from a syndicated feed.)


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