They detect antibodies against the coronavirus that could replace booster doses

The coronavirus pandemic is still affecting humanity. Although the number of cases has recently decreased, there are people who can still catch the virus. Until now, 64% of the world population received the primary vaccination scheme. 31% agreed to booster doses, which are applied because the protection of the primary regimen declines over time.

Faced with the possibility of new variants emerging in the future, there are Israeli researchers they made a Advance which can become an option for booster doses are not needed in the future. For the moment, and while that option continues to develop, the reinforcements must be applied.

Globally, the number of weekly COVID-19 cases decreased by 12% during the week of August 29 to September 4 last compared to the previous week, with just under 4.2 million new cases reported according to the World Health Organization. The number of weekly fatalities decreased 5% compared to the previous week, with more than 13,700 victims reported. To prepare for the future there is a lot of research going on. On the one hand, specific booster doses against Omicron have been developed. There are also four vaccines that are given by mouth or nose. In addition, there is now the possibility of developing an intervention that could act against all current or emerging variants.

This possibility arises from an investigation of the Tel-Aviv University. Scientists from that institution, led by Natalia Freund, managed to isolate two antibodies that neutralize all known variants of COVID-19, including Ómicron, which is the predominant one this year. It works with an efficiency of up to 95%.

Targeted treatment with antibodies and their delivery to the body in high concentrations could serve as an effective substitute for vaccines, especially for populations at risk and those with weakened immune systems. With antibody treatment, there is the potential to eliminate the need for repeated booster shots of the entire population each time a new variant emerges, the scientists estimate.

The researchers demonstrated that antibodies isolated from the immune system of recovered COVID-19 patients are effective in neutralizing all known variants of the virus, including variants Delta and Omicron. According to the researchersthis discovery could eliminate the need for repeated booster vaccinations and boost the immune system of populations at risk.

PhD students also participated in the research. Michael More Y Ruofan Lee, from the Department of Clinical Microbiology and Immunology at the Sackler School of Medicine. The study was conducted in collaboration with Dr. Ben Crocker, from the University of California at San Diego. The teacher Ye Xiang from Tsinghua University in Beijing. The teacher Meital Gal-Tanamy and the doctor Moshe Dessau from Bar-Ilan University also participated in the study. The study has been published in the journal Nature Communications Biology.

The study is the continuation of preliminary work that had been carried out in October 2020, in the midst of the COVID-19 crisis. At the time, Dr. Freund and her colleagues sequenced all the immune system B cells in the blood of people who had recovered from the original strain of the coronavirus in Israel, and isolated nine antibodies that the patients produced. Researchers have now found that some of these antibodies are highly effective at neutralizing the new variants of the coronavirus, Delta and Omicron. Clinical trials evaluating the efficacy and safety of antibodies as therapies will be needed.

According to Freund, “In the previous study, we showed that the various antibodies that are formed in response to infection with the parent virus are directed against different sites on the virus. The most effective antibodies were those that bound to the Spike protein of the virus, in the same place where the Spike binds to the cellular receptor ACE2. Of course, we were not the only ones to isolate these antibodies, and the world health system made extensive use of them until the arrival of the different variants of the coronavirus, which in fact rendered most of these antibodies useless.

“In the current study, we show that two other antibodies, TAU-1109 and TAU-2310, bind to the Spike protein of the virus in a different area from the region where most antibodies were concentrated until now. (and therefore less effective at neutralizing the original strain) they are actually very effective at neutralizing the Delta and Omicron variants. According to our results, the efficacy of the first antibody, TAU-1109, to neutralize the Omicron variant is 92%, and to neutralize the Delta variant, 90%. The second antibody, TAU-2310, neutralizes the Omicron variant with an efficiency of 84%, and the Delta variant with an efficiency of 97%”.

According to Dr. Freund, the surprising effectiveness of these antibodies could be related to the evolution of the virus: “The infectivity of the virus increased with each variant because each time the amino acid sequence of the part of the Spike protein that binds to the ACE2 receptor changed., thus increasing its infectivity and at the same time evading the natural antibodies that were created after vaccinations. In contrast, the TAU-1109 and TAU-2310 antibodies do not bind to the ACE2 receptor binding site, but to another region of the Spike protein – an area that for some reason does not undergo many mutations – and that is why they are effective to neutralize more viral variants. These discoveries arose when we tested all variants of the coronavirus known to date.”

The two antibodies, cloned in Dr. Freund’s laboratory at Tel Aviv University, were sent to test their efficacy against live viruses in cultures. at the University of California San Diego, and against pseudoviruses at the Bar-Ilan University School of Medicine laboratories in Galilee. The results were identical and equally encouraging in both tests.

Freund believes that antibodies can be a real revolution in the fight against COVID-19: “We have to consider the COVID-19 pandemic in the context of previous disease outbreaks that humanity has seen. People who were vaccinated against smallpox at birth and who are 50 years old today still have antibodies, so they are probably at least partially protected against the monkeypox virus that we have recently heard about.”he pointed.

Unfortunately, this protection from the smallpox vaccine has not also been given with respect to coronavirus vaccines. “For reasons we don’t fully understand yet, the level of antibodies to COVID-19 declines significantly after three months, which is why we see people getting infected again and again, even after being vaccinated three times.” , warned the researcher.

“In our opinion, selective antibody treatment and its administration to the body in high concentrations can serve as an effective substitute for repeated booster doses, especially for populations at risk and those with weakened immune systems. COVID-19 infection can cause severe illness, and we know that providing antibodies in the first few days after infection can stop the spread of the virus. So it’s possible that by using effective antibody treatment, we won’t have to boost the entire population every time there’s a new variant,” he estimated.

consulted by Infobaethe doctor Laura Bover, Argentine scientist and director of monoclonal antibodies at the MD Anderson Center in the United States assessed the results of the research published in the journal Nature Communications Biology. “When antibodies are generated, the most important step, as César Milstein himself recommended, is the screening. In other words, testing is key to selecting the most effective antibodies to achieve the proposed objective., either therapeutic or for use in diagnosis or localization of the ‘target’ molecule of study in tissues”, he explained.

The group led by a scientist from Israel – pointed out Dr. Bover – “isolated genetic material of antibodies from antibody-producing plasma cells, built recombinant antibodies and tested them against the receptor binding domain of all the variants mentioned in the study. They selected those that bound with greater affinity, and neutralized more both viral particles and pseudoviruses, also introducing specific mutations present in the different variants and measuring how these parameters are affected. That selection process is what allows them to choose the best candidates to join and neutralize known variants.”

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