Researchers are looking for strong antibodies against many mutants.Breakthrough cases may be less infectious

August 23 (Reuters)-This is a summary of some recent research on COVID-19. They require further research to support the findings and include studies that have not yet been certified by peer review.

Researchers working on one vaccine for many variants

Last week, two separate research teams reported on laboratory trials of monoclonal antibodies that appear to protect against a wide range of COVID-19 virus variants.One study published on Wednesday New England Journal of MedicineIdentifyes “high-level broad-spectrum” antibodies in blood samples from survivors of the first SARS outbreak in 2003 who recently received the Pfizer / BioNTech vaccine against SARS-CoV-2, the virus that causes COVID-19. Did. In in vitro experiments, some of the vaccine-induced SARS survivor antibodies may have been identified in bats and scales, as well as in all of the SARS-CoV-2 variants of current concern. Five viruses can also be neutralized. To cause human infections.Another study was published in the journal on Thursday Immunity, Another research team describes a low-dose, highly protected antibody against a wide range of mutants that cause COVID-19 in mice. “Antibodies attach to some of the viruses that differ little between mutants, which means that resistance is unlikely to develop here,” the authors said. The findings from these studies could be a step towards developing new antibodies that are effective against multiple different coronaviruses, the two teams said.

In breakthrough cases, reduced infectious virus shedding may occur

New studies suggest that people vaccinated with COVID-19 have high levels of the virus in their nose and throat, but not all of the viruses are infectious. Of the 24,706 vaccinated health care workers in the Netherlands, 161 developed mild or asymptomatic breakthrough infections. This is mainly due to the delta variant of coronavirus. Virus levels in these patients’ nose and throat swab samples were as high as unvaccinated health workers who were infected with the original strain of the virus last year. However, in in vitro experiments, viruses from vaccinated patients were less efficient at self-renewal than viruses from unvaccinated patients. Researchers speculate that it was probably neutralized by antibodies from the vaccine.In the report posted to medRxiv On Saturday, prior to peer review, they conclude that infectious virus shedding is reduced in breakthrough cases, even though the patient is still contagious.

Antibodies decline faster after vaccination and after actual infection

According to Israel’s largest HMO doctor, recipients of the mRNA COVID-19 vaccine from Pfizer / BioNTech have a faster decrease in protective antibody levels than COVID-19 survivors. They tracked antibody levels in 2,653 adults who were vaccinated twice and 4,361 unvaccinated survivors of COVID-19. Antibody levels decreased by up to 40% per month in vaccinated participants, but decreased by less than 5% per month during the so-called convalescent period. After 6 months, about 84% of vaccinated patients still had detectable antibodies, while about 90% of convalescent patients still had detectable antibodies after 9 months. .. Dr. Ariel Israel of Leumit Health Services, co-author of a report posted on Sunday medRxiv Prior to peer review, it was noted that antibodies are not the only weapon of the immune system against the virus. Nevertheless, the data suggest that Pfizer vaccine recipients’ antibody protection is diminished at a higher rate than COVID-19 survivors, he said. Leumit researchers Previously reported Its breakthrough infection rate increases from about 5 months after vaccination. Dr. Israel said the combined data claim booster shots five months after the second injection, especially for high-risk individuals.

Click Reuters graphics About the vaccine under development.

Report by Nancy Rapid; Edited by Tiffany Wu

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