Researchers last year showed that there remains an elite school in the lymph nodes where B cells train, called germinal centers. Active for at least 15 weeks After the second inoculation of the Covid vaccine.With updated research Published in the journal NatureThe same team showed that six months after vaccination, Memory B cells continue to mature and the antibodies they produce continue to acquire the ability to recognize new mutants.
“These antibodies are better binders and stronger neutralizers than the antibodies produced one month after immunization,” said Ali Ellebedy, an immunoscientist at Washington University in St. Louis, who led the study. Says.
In the latest study, another team has shown that the third shot creates a more abundant pool of B cells than the second shot, and the antibodies they produce recognize a wider range of mutants. rice field. In laboratory experiments, these antibodies were able to dodge beta, delta, and omicron variants. In fact, studies have shown that even if the vaccine was not designed for the variant, more than half of the antibodies found one month after the third dose were able to neutralize Omicron.
“When you take the third dose, you get a rapid response and there is considerable specificity for Omicron, which explains why people who received the third dose are so much better. “More,” said Michel Nussenzweig. , An immunological scholar at Rockefeller University who led the study.
Memory cells generated after infection with the coronavirus rather than the vaccine do not appear to be very potent against the Omicron mutant. Studies show It was published in Nature Medicine last month. The immunity produced by the infection “changes considerably, but the vaccine response is much more consistently good,” said Marcus Bagato, an immunoscientist at the Karolinska Institute in Sweden, who led the study.
Most people, whether vaccinated or not, show only a slight decrease in T cell response to Omicron, but about 1 in 5 have a “significant decrease in response” of about 60%. Dr. Bagato said he did. He said the difference was most likely due to their underlying genetic makeup.
Still, recent studies suggest that for most people, the immunity gained from infection or vaccination will last for a long time. Experts say that even if a mutation in a new variant alters some of the viral regions recognized by T cells, there are still enough other regions to maintain a reasonably strong immune response.