Study in Israel of fully vaccinated people provided clues to decide who will need boosters

In Israel, 64% of the population has already had access to at least one dose of COVID-19 vaccines. 59% received the complete immunization schedule. Since last December, the country’s plan has progressed rapidly with the application of messenger RNA vaccines and has reached 123 doses applied per 100 inhabitants. Worldwide, the average is 52 doses applied per 100 inhabitants. Following the advances in vaccination, scientists and health authorities conducted various studies on the effectiveness of real-time inoculants, and strengthening adjustments were initiated based on the least protected groups. Today, Israel has decided that it will reinforce the elderly. He was already applying it to immunocompromised people.

In the context of a pandemic, with a rapid vaccination plan but with epidemics as is the case in Israel, yesterday a study was published in the journal New England Journal of Medicine who evaluated the protection generated by vaccination in health workers after the two doses in this country. He found that some people may have a much lower level of protective antibodies than other inoculated people. As a result of this situation, these people may be at greater risk of becoming infected. That is, they were fully vaccinated, but they got infected.

The research was conducted at Tel Hashomer Sheba Medical Center. The discovery could represent a key to understanding who should receive a third vaccine, said Dr Gili Regev-Yochay, director of Sheba’s infectious disease epidemiology unit and lead author of the study.

“The study conducted in Israel contributes to a better understanding of the impact of vaccination and the risk that people who are already immunized will be infected.. It reveals that the incidence of infection in fully vaccinated subjects is very low ”, commented to Infobae Javier Farina, member of the Argentine Society of Infectology (SADI) and head of infectology at the Hospital de Alta Complejidad Cuenca Alta, in Cañuelas, province of Buenos Aires.

Dr Farina also pointed out that Although there were few cases, most of those previously vaccinated were infected by people who had not received the doses. “A very important piece of information is that the vaccinated people who were infected did not generate secondary infections,” said Farina. “It should also be considered that all those vaccinated were followed up with the use of PCR technology, which made it possible to identify all the infections.”

Sheba documented 39 vaccinated cases out of a total of 11,000 health workers who had been fully vaccinated. When they were studied and it had been at least ten days since the second injection of Pfizer – within the previous three months.

As Regev-Yochay explained, the average age of those infected was 42.5 years old. About a third of those vaccinated and infected had symptoms without symptoms. 10% had very mild symptoms; 21% had a fever and 19.4% had so-called ‘post-Covid symptoms’ – from loss of taste and smell to exhaustion – for more than six weeks.

In addition, nearly 5,000 healthcare workers have undergone routine serological testing. The researchers were able to compare the antibody level of those who were infected – measured just before the virus was detected – with that of other staff members with similar characteristics (gender, age, general health, among other criteria. ) that have not been infected. . . .

“What we saw was that people who were infected had three times less neutralizing antibodies than those who were not infected. Considering the antibody peak recorded after inoculation, the level of infected people was seven times lower than that of uninfected people. It was the most important part of the study, ”Regev-Yochay said at a press conference.

“This is why a study on a relatively small group of individuals was published in such a prestigious journal,” noted Regev-Yochay. In addition, the study also documented a link between the level of antibodies and viral load – the number of viral particles in the body – which is directly related to the level of infectivity of a person with the coronavirus.

“People who had a higher level of neutralizing antibodies also had a lower viral load, which meant they were more likely to infect other people,” the doctor said. “It also shows that people who are vaccinated are less likely to infect other people.”

About 85% of the cases considered in the study were infected with the worrying variant Alpha, which was detected in England last year, as the investigation was conducted at a time when the Delta variant was not yet present in Israel. Currently, the variant that predominates in cases diagnosed in this country is Delta. In the United States, this variant has led to an increase in cases and the reuse of chinstrap in people previously vaccinated.

Due to the impact of vaccination on reducing cases from January to May, hospitalizations and deaths from COVID-19 declined in Israel. The government of this country has started to relax its restrictions. But at the end of June, cases increased further. More than a thousand people have tested positive every day, prompting Israel to reinstate some restrictions last week.

New research published in the New England Journal of Medicine reaffirmed that the correlation between antibodies and the level of protection given by vaccines is still relevant, according to Dr Regev-Yochay. While research does not shed light on how the vaccine’s effectiveness declines over time, the link between antibody level and infection may help determine who needs a third vaccine most. the coronavirus..

“I think these data on the correlation between antibodies and infection are important to understand what is the population at risk and from there maybe start thinking about who should get a third dose and when»Concluded Regev-Yochay.

On July 11, Israel’s health ministry began offering a third dose of the COVID-19 vaccine to severely immunocompromised adults. At the time, it became clear that the recommendation for the booster dose was to increase antibody levels in immunocompromised people. It included cancer patients, liver transplant recipients and others who have recently shown weakened vaccine protection.

As, Today, July 29, the expert committee of the Israeli Ministry of Health approved the recommendation to inoculate elderly people with a third dose of the messenger RNA vaccine developed by the Pfizer / BioNTech companies. likely to develop serious illness from the coronavirus.

The decision was taken by absolute majority, although there are differences as to the age from which this strengthening of vaccination should begin, with opinions ranging between 60 and 70 years. Today, 2,165 cases of COVID-19 have been recorded. This report is the third day in a row above 2,000 infections, for a total of 868,045 confirmed, with 6,463 deaths.

KEEP READING: