Two days after a report by international experts ruled out, due to lack of data, that the third dose of the covid vaccine improves the immunity of the general population, the Israeli Ministry of Health has released the results of the first study on Wednesday on people revaccinated with a booster injection. The research carried out from July 1, when Israel began to offer the new inoculation with the Pfizer-BioNTech vaccine, by universities and hospitals among one million patients, concludes that those inoculated with the third dose have rates of contagion with infections bass up to 10 times less compared to those who have only received the first two punctures.
The Israeli study - led by an interdisciplinary group from the Hebrew University of Jerusalem, the Haifa Technion, the Tel Aviv Sheba Hospital and the Weizmann Institute of Science, together with the Ministry of Health and other research centers - has been reviewed by experts before publication in the American medical journal
The New England Journal of Medicine
. Their results show that the third dose has reduced the rates of contagion and serious infections among those over 60 years of age by one month. This population was the first to receive the booster injection in Israel, one of the few countries that has generalized the revaccination campaign and a pioneer in implementing it.
The study comes out just one day before a meeting of an advisory committee of the United States Drug Administration (FDA) is held this Friday to discuss the administration of a third booster dose of the Pfizer vaccine. After the non-binding vote of the committee, the same one that recommended the emergency authorization of the vaccine in December, the FDA must decide whether to update its authorization of the drug to include the third dose for the general population (which it already authorized in August for the immunosuppressed) . The pharmacist has been trying to convince the agency for weeks that the available data supports her request for authorization of a booster dose.
The Israeli health system has so far inoculated about three million people with an extra dose: a third of the inhabitants of the Jewish state and around half of its population over 12 years of age. However, the authors of the report are healed in health by warning that new studies will be necessary to determine the long-term efficacy of the third dose against the delta variant or others that may arise in the future.
Divided into two cohorts of patients - with booster and without booster - the study on one million people susceptible to receiving the vaccine counted 4,439 new cases of covid-19, of which 294 cases were serious, among those who had not received the third doses, compared to 934 and 29, respectively, among those revaccinated at least 12 days before. The rate of serious infections turned out to be 10 times lower for the booster group, although a second stricter analysis of the study data - differentiating the behavioral habits between the two cohorts - found that the rate was actually five times lower.
The review with statistical models to refine the results of the study also reflects the escalation of protection offered by vaccines against covid. If people immunized six months ago with the first two doses are half as likely to get the delta variant as those not vaccinated, those injected with the booster dose only have a 5% risk of infection. That is, the efficacy of revaccination rises to 95%, equivalent to that offered by the second dose two weeks after its application, with the less contagious alpha variant, as published by the
New England Journal of Medicine,
according to with an information note distributed by the Israeli Ministry of Health.
The Israel study appears to respond, at least partially, to the assertions of a group of experts from the FDA and the World Health Organization (WHO), who highlighted that there is no solid evidence that a third dose is necessary. vaccine for the general population. These researchers did a review of clinical trials on the effectiveness of vaccines and analyzes on their performance in different countries. The work, published Monday in the British medical journal
The Lancet,
maintains that the efficacy of the drugs remains very high against all variants of the coronavirus, including delta.
"The body of evidence accumulated so far seems to show that there is no need for a third dose in the general population, since its protection against severe disease is still high," the authors stated.
A health worker takes a sample from a child for a covid detection test, on September 3 in Jerusalem.ABIR SULTAN / EFE
"Although it may provide some advantage, the benefits of immunizing the unvaccinated are much greater", highlighted the work published by
The Lancet,
since "it can accelerate the end of the pandemic, and will prevent more variants of the coronavirus from evolving." The WHO has called for the imposition of a moratorium on the application of revaccination in the most developed countries as long as minimum levels of protection have not been reached in poor countries.
Israel has settled into the paradox of having gone from a pioneer country in vaccination to a leader in per capita infections.
This was confirmed by a study by the University of Oxford in the last week of August, with more than a thousand new cases registered every day per million inhabitants at the height of the delta variant wave.
With an average of more than 10,000 positives a day, the record for daily infections registered in January at the height of the pandemic was surpassed.
This Tuesday, the Ministry of Health has again reported an infection rate that exceeds the bar of 10,000 cases after more than a week of reduction in morbidity.
The paradoxes of a pioneer country
With more than 60% of its population fully vaccinated for almost half a year and the only one in the world that has already immunized a third of its inhabitants with the third dose - in both cases, with rates that are close to 100% among those older than 50 years - Israel is also burdened by the way out of the pandemic. About a million people over 12 years of age (12% of its inhabitants) have refused to be vaccinated and almost 25% of those under 12 years of age cannot yet receive the inoculation. Coinciding with the beginning of the school year, the students in this last group are being subjected to continuous tests for the detection of covid, in order to isolate those infected. Health officials consider this to be one of the main causes of the high rate of infections, mostly with mild symptoms.
Israel has a strong public health system interconnected with state-of-the-art databases, and is relatively isolated by strict border control. In the large-scale immunization campaign launched in January, Israeli authorities were accused of using citizens as guinea pigs in a large-scale clinical trial to ensure a rapid and preferential supply of vials of Pfizer-BioNTech, in exchange for share general patient data and clinical study results with the laboratories that designed the vaccine. The criticism ceased after the success of the campaign, which managed to reduce the incidence of covid from the thousand cases per million inhabitants registered in January to just two new infections per million in June.
The Ministry of Health is now questioning whether the causes of the rebound in the pandemic have been due to the delta variant, the reduction in immunity offered by vaccines over time, or both causes.
The US company Pfizer, the only effective vaccine supplier to the Israeli health system, has already prepared a commercial campaign "with levels equivalent to those of viagra in the past" to boost sales of its drug against the coronavirus, according to an information from the
Financial Times.
In addition to what the FDA may decide in the US, France and Germany are also studying extending revaccination.
Spain only raises it for now to protect vulnerable groups such as the severely immunosuppressed, and is studying extending it to people with cancer and the elderly in nursing homes.