New COVID-19 variant BA.2.86 is unlikely to cause a new wave of infections

Multiple laboratory studies show: New COVID-19 variant BA.2.86 is unlikely to cause a new wave of infections.

BA.2.86 may be  not as serious as people fear, and may be unlikely to cause a new wave of infections.

Recently, a new coronavirus variant BA.2.86 carrying a large number of mutations has been detected in multiple countries.

How transmissible and capable of escaping previous immunity is it?

Early studies from multiple laboratories around the world have shown that after testing the antibodies of people who have been vaccinated against the coronavirus and those who have been infected with the coronavirus, these pre-existing antibodies can recognize and resist new coronavirus variants, including the highly mutated BA.2.86. For people who have been infected with the Omicron XBB variant within six months, this immune protection is even better.

The latest studies come from two independent US research laboratories. The researchers found that compared with the currently prevalent XBB variant, BA.2.86 does not have further immune escape ability. This result is consistent with previous early experiments from Chinese and Swedish laboratories.

A team led by He Dayi, professor of microbiology and immunology at Columbia University in the United States, used plasma from 61 adults for the study, of which 17 received three doses of monovalent vaccine and two doses of bivalent vaccine, 25 had been infected with the BA.2 variant, and 19 had been infected with the XBB variant. The study found that the antibodies in these people’s blood could recognize the BA.2.86 variant, and the people with the strongest immunity to BA.2.86 were those who had recently recovered from XBB variant infection.

Another US research team also reached similar conclusions. This is surprising because the BA.2.86 variant carries more than 30 mutations. Scientists predicted that based on their understanding of these specific mutations, BA.2.86 might have a high degree of immune escape ability.

This means that BA.2.86 may be a “paper tiger” and not as serious as people fear, and may be unlikely to cause a new wave of infections.

Last month, Chinese researchers conducted experiments using vaccinated mice and blood from vaccinated and recently infected people. A team led by Cao Yunlong from Peking University Biomedical Innovation Institute found that although BA.2.86 can escape some immunity compared with earlier variants of the coronavirus, this escape ability is negligible compared with the immune escape ability of previous variants.

The researchers also found that the infectivity of the BA.2.86 variant was about 60% lower than that of the XBB.1.5 virus, which can explain why BA.2.86 has been found in many countries but has a low level of transmission – because it cannot compete with other rapidly prevalent variants.

Researchers from the Karolinska Institute in Sweden also concluded through research that the BA.2.86 variant is not as “fierce” as Omicron was when it first appeared.

But it should be pointed out that all these studies have limitations, because the researchers used BA.2.86 pseudoviruses for testing in the laboratory, not the virus itself, and further research is needed in the future.