A combination of vaccination and naturally acquired infection appears to boost the production of maximally potent antibodies against the Covid-19 virus, said researchers from University of California - Los Angeles Health Sciences in a study published in peer-reviewed journal mBio.
Thus, it raised the possibility that vaccine boosters may be equally effective in improving antibodies’ ability to target multiple variants of the virus, including the delta variant, which is now the predominant strain, and the recently detected omicron variant. (The study was conducted prior to the emergence of delta and omicron, but Dr. Otto Yang, the study’s author, said the results could potentially apply to those and other new variants.)
“The main message from our research is that someone who has had COVID and then gets vaccinated develops not only a boost in antibody amount, but also improved antibody quality — enhancing the ability of antibodies to act against variants,” said Yang, a professor of medicine in the division of infectious diseases and of microbiology, immunology and molecular genetics at the David Geffen School of Medicine at UCLA. “This suggests that having repeated exposures to the spike protein allows the immune system to continue improving the antibodies if someone had COVID then been vaccinated.”
Yang said it is not yet known whether the same benefits would be realized for people who have repeated vaccinations but who have not contracted COVID-19.
“Overall, our findings raise the possibility that resistance of SARS-CoV-2 variants to antibodies can be overcome by driving further maturation through continued antigenic exposure by vaccination, even if the vaccine does not deliver variant sequences,” the study says. It suggests that repeated vaccinations may have the capacity to accomplish the same thing as getting vaccinated after having had Covid-19, although further research will be required to address that possibility.
The study’s other authors are F. Javier Ibarrondo, Christian Hofmann, Ayub Ali, Paul Ayoub and Dr. Donald Kohn, all of UCLA.