Experts say the new BA.2.86 variant requires intense monitoring and vigilance that many of its predecessors did not. That’s because it has even greater potential to escape the antibodies that protect people from getting sick, even if you’ve recently been infected or vaccinated.
There have only been about a dozen cases worldwide of the new variant. It is not yet known if it will be transmissible enough to cause a surge.
“This is a radical change of the virus like what happened with omicron, which caught a lot of people defenseless. Even if they had a vaccine or prior infection, it could still get into them and infect them again or for the first time. We are facing that again.”Eric Topol, director of the Scripps Research Translational Institute
This latest covid variant could be the best yet at evading immunity – Washington Post
Why are Scientists Following BA.2.86 So Closely?
After Omicron appeared, SARS-CoV-2 evolution began to follow a fairly predictable course: successful variants emerged from circulating lineages after gaining a few key mutations that enabled their spread. BA.2.86, by contrast, is drastically different from widespread coronavirus variants, and in this way its emergence is reminiscent of that of Omicron and early pandemic variants including Alpha and Delta.
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. For this reason, there is a good chance that the variant will be able to escape some of the neutralizing antibodies triggered by previous infections and vaccine boosters.
Another feature of BA.2.86 that has piqued scientists’ interest is its geographical distribution. None of the cases identified so far seem to be linked. This suggests that the variant might already be fairly widespread.
“I don’t think anybody needs to be alarmed by this. The most likely scenario is that this variant fizzles out, and in a month nobody other than people like me even remember that it existed.”Jesse Bloom, viral evolutionary biologist at the Fred Hutchinson Cancer Center
Why a highly mutated coronavirus variant has scientists on alert. Nature, 21 August 2023.
CDC Updates Risk Assessment
Based on what CDC knows now, existing tests used to detect and medications used to treat COVID-19 appear to be effective with this variant. BA.2.86 may be more capable of causing infection in people who have previously had COVID-19 or who have received COVID-19 vaccines.
Scientists are evaluating the effectiveness of the forthcoming, updated COVID-19 vaccine. CDC’s current assessment is that this updated vaccine will be effective at reducing severe disease and hospitalization. At this point, there is no evidence that this variant is causing more severe illness. That assessment may change as additional scientific data are developed.
As of August 23, 2023, 9 BA.2.86 variant sequences have been reported globally: Denmark (3); South Africa (2); Israel (1); United States (2) and United Kingdom (1). One of the cases in the United States is in a person detected through CDC’s Traveler-based Genomic Surveillance. The identification of these cases in multiple geographies is evidence of international transmission. Notably, the amount of genomic sequencing of SARS-CoV-2 globally has declined substantially from previous years, meaning more variants may emerge and spread undetected for longer periods of time. It is also important to note that the current increase in hospitalizations in the United States is not likely driven by the BA.2.86 variant.
With only nine sequences detected, it is too soon to know how transmissible this variant is. Detection across multiple continents suggests some degree of transmissibility.
A U.S. wastewater sample that was collected as part of routine monitoring in the National Wastewater Surveillance System (NWSS) has preliminarily indicated the presence of the BA.2.86 variant. Scientists are investigating this sample and will continue to closely monitor wastewater for further or more widespread evidence of BA.2.86.
The large number of mutations in this variant raises concerns of greater escape from existing immunity from vaccines and previous infections compared with other recent variants. For example, one analysis of mutations suggests the difference may be as large as or greater than that between BA.2 and XBB.1.5, which circulated nearly a year apart. However, virus samples are not yet broadly available for more reliable laboratory testing of antibodies, and it is too soon to know the real-world impacts on immunity.
Examination of the mutation profile of BA.2.86 suggests that currently available treatments like Paxlovid, Veklury, and Lagevrio will be effective against this variant.
Risk Assessment Summary for SARS CoV-2 Sublineage BA.2.86. Centers for Disease Control and Prevention, 23 August 2023.