New COVID-19 variant puts scientists on alert

COVID-19 testing has picked up a new coronavirus variant called BA.2.86 – nicknamed Pirola, after an asteroid – in several countries.

Whether this highly mutated variant has the potential to spread at the speed of light and would be of global concern is something researchers are trying to find out.

BA.2.86 is far different as it carries more than 35 mutations in the spike protein compared with XBB.1.5, the dominant variant through most of 2023. It is believed the mutations could dodge the body's immunity from prior infections or vaccination.

Dr Adam Lauring, a virologist and infectious-disease physician at the University of Michigan in Ann Arbor, Michigan, US, whose laboratory has identified one case of BA.2.86, said there is a good reason to think that the new variant will not have the same impact as Omicron had. “Still, it’s early days to know the real-world impacts .”

Nine BA.2.86 sequences thus far

There have been nine BA.2.86 sequences reported to date globally – 3 in Denmark, 2 in South Africa, 1 in Israel, 2 in the US, and 1 in the UK – that the WHO designated it  as a “variant under monitoring.”

The US Centers for Disease Control and Prevention meanwhile said there is no evidence at this point that BA.2.86 is causing more severe illness.

The lineage appeared to be from the BA.2 Omicron subvariant, which caused large case spikes in early 2022. Many of the changes in BA.2.86 are in regions of the spike protein that are targeted by the body’s potent infection-blocking, or neutralizing, antibodies, said Dr Jesse Bloom from the Fred Hutchinson Cancer Research Center and an affiliate professor of genome sciences and microbiology at University of Washington, Seattle, Washington, US. “This is why there is a good chance that BA.2.86 can escape some of the neutralizing antibodies triggered by vaccine boosters and previous vaccinations.”

In a better place than before

While neutralising antibodies provide the best protection against infection, there are also broader mechanisms of immunity elicited by vaccination and infection that provide some protection against severe disease even for heavily mutated variants, he explained. “So even if this Omicron offshoot variant starts to spread, we will be in a better place than we were in 2020 and 2021 to fight the infection, since most people already have immunity to SARS-CoV-2.”

Bloom said another feature of BA.2.86 that had generated interest from experts is its geographical distribution. None of the cases that have been identified so far were linked. “This suggests that the variant might already be widespread.”

Amid news of the new variant, the latest version of the COVID-19 vaccine, a monovalent one, is expected to be rolled out in the US this month. The vaccine is specifically designed against the Omicron subvariant XBB.1.5.