Large study from Israel shows that Pfizer vaccine reduces infection rate

Israel’s largest health maintenance organization (HMO), the Clalit Health Fund, published the results of the first major research on the effects of Pfizer’s Covid-19 vaccine. Clalit examined 200,000 people aged 60 and over who received the vaccination and needed a Covid-19 test, with 200,000 who were not vaccinated and also needed to be tested, and examined the percentage of positive Covid-19 tests between each group.

Between the fifth and the twelfth day after vaccination, there was still no difference in the number of positive tests between the two groups. However, from 14 days after vaccination, there was a significant drop of 33% in the percentage of people with a positive test who received the vaccination, compared to those who did not.

Given that the vaccinated group still needs a second Pfizer vaccination to build full immunity, the results found by Clalit were in line with expectations. In its trial, Pfizer found that the effects of the first vaccination began after 11 days. The similarity between the Clalit survey in Israel and the Pfizer test results reinforced the feeling that the smallest percentage of people who tested positive were from the vaccine and not from other variables.

The director of the Clalit Research Institute, Prof. Ran Balicer explained that while Pfizer’s research was based on people who experienced symptoms of Covid-19, Clalit’s research included people from both groups who came to be tested because they experienced symptoms, but also others who came into contact with someone diagnosed with Covid-19.

Clalit’s research also corresponds to a smaller project conducted by Prof. Gili Regev, Director of the Infectious Diseases Epidemiology Unit at Sheba Medical Center in Tel Hashomer, near Tel Aviv. She examined 200 people who received their first vaccination and found that after a week, only 1% had developed enough antibodies to provide immunity, but that number rose to 50% after two weeks.

Prof. Balicer said: “We are hoping to cross-check the data that we are monitoring over time in order to confirm these findings. But the results coincide in terms of the timeline and the trend that we saw in the controlled research of vaccine producers.”

Meanwhile, the virus has worsened in Israel. For the second consecutive day, the Ministry of Health reported more than 9,000 new cases of Covid-19, although the number of serious cases has stabilized at just over 1,000.

This ability to provide Pfizer with real-time data on the protection offered by the vaccine is one of the main reasons why the company has provided Israel with so many millions of doses.

Published by Globes, business news from Israel – en.globes.co.il – on January 13, 2021

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