French study of 22 million cases confirmed high efficacy of COVID-19 vaccines

The Vaccination against COVID-19 reduces risk of developing severe disease by 90% in people over 50 and it also seems effective against the delta variant, according to a large study conducted in France.

“Vaccinated people nine times less likely to be hospitalized or die from COVID-19 than unvaccinated people», He explained to the AFP the epidemiologist Mahmoud Zureik, director of the Epi-Phare structure, which associates the Health Insurance (Cnam) with the Medicines Agency (ANSM), responsible for preparing the report.

These data, obtained from 22 million cases, confirm the conclusions of other studies carried out in Israel, the United Kingdom or the United States. Corn the French report is “the most complete fact in the world”Zureik noted.

Researchers compared the situation of 11 million vaccinated people over the age of 50 with another 11 million unvaccinated people of the same age group between December 27, 2020 (start date of vaccinations in France) and July 20.

Two weeks after the injection of the second dose, scientists observed “A reduction in the risk of hospitalization of more than 90%”.

Insufficient data on the delta variant

The authors of the report also analyzed the efficacy of vaccines against the delta variant, which emerged in India and is currently dominant in the world. To do this, they used data from a single month, between June 20 and July 20.

According to this information, they observed a 84% efficiency in those over 75 years old and 92% in 50-74 year olds. However, “this period is too short to assess the real impact of vaccination on this variant,” Zureik acknowledged.

“The study will continue to include data for August and September,” he added.

This verification of the effectiveness of vaccines is also done with injections with Pfizer / BioNtech, Moderna and AstraZeneca. Janssen’s immune substance is the fourth approved in France, but it was injected into so few people that it was not included in the study.

“This decrease is at the same level as the risk of dying during a COVID-19 hospitalization,” said Epi-Phare.

Besides, the efficacy on severe forms of the disease “does not seem to decrease over the five-month period studied”.

“An epidemic without serious forms”

The study is divided into Two parts: one for people over 75 years old (7.2 million cases analyzed) and another for 50-74 year olds (15.4 million cases). The vaccination campaign in France began on December 27 for the first age group and between February 19 and May 10 for the second.

The study covered these two age groups until July 20, with similar efficacy results.

To compare hospitalization data, they matched a vaccinated person with an unvaccinated person of the same age, gender, and region.

The report only looked at the risk of developing severe forms of the coronavirus and was not interested in the possibility of becoming infected and transmitting the virus.

Other studies had already shown that the delta variant reduced the effectiveness of vaccines against the risk of contracting COVID-19. However, avoiding severe forms is “the primary goal of public health,” Zureik said. “An epidemic without severe forms is no longer an epidemic,” he said.

(With information from AFP / By Paul Ricard)

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