Pfizer's vaccine is 85% effective in a single dose, according to a study in Israel

A medic prepares a dose of Pfizer's vaccine at Sheba Hospital on Jan. 12. Oded Balilty / AP

The first dose of the Pfizer-BioNTech vaccine shows an 85% effectiveness against symptomatic COVID-19 infections, according to a study carried out among more than 7,000 workers at the Sheba hospital, in the metropolitan area of ​​Tel Aviv, one of the older than Israel.

The research, published by the medical journal

and cited by Reuters, confirms the drastic reduction in the rate of infected between 15 and 28 days after receiving the initial inoculation.

On the total of those infected by the coronavirus, including the asymptomatic, the level of protection of the vaccine is set at 75%.

The debate on the possibility of limiting immunization to a single dose of the two recommended, in view of the shortage of supply of vials in most of the countries, is rekindled after the publication of this study.

Two Canadian researchers on Wednesday endorsed the strategy adopted by the United Kingdom of using only one dose of the Pfizer and Moderna vaccines to speed up the immunization of more people and delay the second injection.

In a letter published Wednesday in the

, scientists from the Vancouver Center for Disease Control and the Quebec National Institute of Public Health argued that the first dose of Pfizer is 92.6% effective, according to studies. from the pharmaceutical company itself and from the US Administration.

• Pfizer's vaccine reduces symptomatic cases by 94%, according to a study of 1.2 million Israelis

For now, Pfizer has limited itself to responding through a statement that "alternative vaccine dosage regimens" have not yet been evaluated, and that its researchers are conducting their own analyzes on "the effectiveness in real life (of vaccine) in various parts of the world, including Israel ”, where he also studies the potential of the vaccine against emerging variants of covid-19.

The manufacturing laboratory considers that the decision to apply only the first dose at first corresponds to the health authorities of each country.

Sheba Hospital analyzed coronavirus infections among 7,214 health workers who received the first dose of Pfizer in January, at the height of the third wave of the pandemic in Israel.

However, the epidemiologist at this center Gili Regev-Yochay has specified that almost the entire population analyzed in the study is "young and healthy."

"We don't have many employees over 65 in our teams," he told the Hebrew press to clarify the effectiveness of the single dose among older people.

Israel leads the per capita vaccination rate globally, with nearly a third of its 9.2 million people immunized with both doses of Pfizer and about half with the first.

Massive studies on your healthcare system are being the first to spread.

One of them pointed out this week that the vaccine reduces symptomatic cases of coronavirus by 94%.

1.2 million of its affiliates participated in this clinical trial by the research institute of the Clalit health insurance company, the largest in the Israeli health system, of which half, unvaccinated, acted as a control group.

Harvard University assisted in the validation of the preliminary results.

The study has also clearly shown for the first time the effectiveness of the vaccine to protect those over 70 years of age.

The tests developed by Pfizer before the sanitary authorities gave it a free pass were not so conclusive, since few individuals of that age participated in them.