‘Vaccination and natural infection boost production of powerful COVID antibodies’

The findings, the scientists said, raise the possibility that vaccine boosters could be equally effective in improving the ability of antibodies to target multiple variants of the virus, including the delta variant, which is now the dominant strain. , and the recently revealed Omicron variant.

The study – carried out by the University of California, Los Angeles (UCLA) – published in the peer-reviewed journal MBO was conducted before the emergence of Delta and Omicron, but according to study senior author Otto Yang, the results could potentially Apply to those and other new forms.

“The main message from our research is that a person who has had COVID-19 and is then vaccinated not only increases the amount of antibodies, but also improves the quality of the antibodies – the ability of antibodies to convert variants. to act against,” said Yang, a professor of infectious diseases and medicine in the divisions of microbiology, immunology and molecular genetics at the David Geffen School of Medicine at UCLA.

“This suggests that repeated exposure to the spike protein allows the immune system to continue improving antibodies if someone who had COVID-19 had been vaccinated,” Yang explained. part of which binds to cells, resulting in infection.

However, Yang said it is not yet known whether similar benefits will be realized for people who have been vaccinated repeatedly but who have not contracted COVID-19.

Another co-author of the study, F. Javier Ibarondo, Christian Hoffman, Ayub Ali, Paul Ayub and Dr. Donald Kohn, all from UCLA. Researchers compared blood antibodies in 15 vaccinated people who had not previously been infected with SARS-CoV-2, the virus that causes COVID-19, with infection-induced antibodies in 10 people who had recently contracted SARS. Were infected with -CoV-2, but not yet vaccinated.

Several months later, 10 participants in the latter group were vaccinated, and the researchers then re-analyzed their antibodies. The majority of people in both groups had received either Pfizer-BioNTech or Moderna two-dose vaccines.

The scientists evaluated how the antibodies acted against a panel of spike proteins with various common mutations in the receptor-binding domain, which are targets for antibodies that help neutralize the virus by preventing it from binding to cells.

They found that receptor-binding domain mutations reduced the potency of antibodies elicited by natural infection or vaccination alone, to roughly the same degree in both groups of people. When the first infected people were vaccinated about a year after natural infection, however, the potency of their antibodies was increased to such an extent that they recognized all the COVID-19 types scientists had tested.

“Overall, our findings raise the possibility that resistance of SARS-CoV-2 variants to antibodies can be overcome by immunization by advancing further maturation through sustained antigenic exposure,” the researchers said in the study. Even if the vaccine does not deliver different sequences.” ,

“Repeated vaccination may have the same potential to accomplish a similar task as post-vaccination with COVID-19, although further research will be needed to address that possibility,” the study said. The study was funded by the AIDS Healthcare Foundation and various private. donors