SAs the COVID-19 pandemic began, health officials warned that the biggest barrier to controlling the virus was its ability to mutate into ever more infectious and dangerous forms.
The latest version raise the alert is an emerging sub-variant of Omicron called BA.2.75.2. It has gained the ability to evade the immunity offered by current vaccines and cannot be neutralized by many currently available antiviral treatments. So far, tension has been report in 47 countries and 39 US states, where it still accounts for less than 1% of COVID-19 cases.
Here’s what we know so far about BA.2.75.2.
Where does BA.2.75.2 come from?
BA.2.75.2, as its nomenclature suggests, emerges from the subvariable BA.2.75. It is growing rapidly, especially in India – although BA.2.75.2 accounts for only 0.5% of cases so far worldwide. Because it has many similarities with the existing auxiliary variable, World Health Organization did not designate BA.2.75.2 as a new variant, but merely referred to it as “the Omicron subvariant being monitored,” meaning health officials should prioritize tracking cases to hopefully prevent prevent the proliferation of infections. Some experts have started to informally call it Centaurus, after Twitter users gave it that nickname.
Why BA.2.75.2 worries public health officials
BA.2.75.2 selected three additional mutations from BA.2.75, two of which are where the virus binds to human cells to infect them.
According to a research by Swedish researchers published on September 16 as a pre-print — meaning the study has yet to be peer-reviewed — these biases are helping BA.2.75.2 avoid all other means. Antibody treatments are currently approved by the US Food and Drug Administration with one exception: bebtelovimab. Made by Lilly, this monoclonal antibody treatment is given intravenously to people with mild to moderate COVID-19 symptoms who are at high risk of progressing to more severe disease. . But because the drug only targets a specific part of the virus’s mutant protein, there’s no guarantee the virus won’t develop mutations to evade it.
On September 7 at New England Journal of MedicineJapanese scientists report The findings were slightly more encouraging in their trials of BA.2.75 than available treatments. They also found that bebtelovimab was able to neutralize the variant, and also report that some of the first antiviral treatments developed — remdesivir and molnupiravir — as well as the latest, Paxlovidstill effective.
But resistance is a feature of BA.2.75.2, which is why health officials are concerned. The Swedish scientists also reported low levels of antibodies against the virus from blood donors, some of whom were vaccinated or recently infected with SARS-CoV-2, against BA.2.75.2 more than five times that of the currently dominant Omicron variant, BA.5. They also found that BA.2.75.2 was resistant to the Avusheld antiviral combination therapy. Taken together, the scientists conclude, this variant “effectively keeps out the current [antibody] immunity in representative “and” populations[s] most well-characterized resistant variant to date. “
How well does the vaccine work against BA.2.75.2?
Currently, the picture is not complete. Human studies about Latest COVID-19 enhanced snapshot—Which targeting two other Omicron sub-variables, BA.4 and BA.5 — is yet to be completed and it is not clear how well they will work for BA.2.75.2. But there are hints from studies involving the original vaccine as to what kind of protection people can expect if this variant becomes more common.
David Montefiori, a viral immunologist at Duke University Medical Center who oversaw testing the effectiveness of Moderna’s mRNA vaccine against new variants, is now studying how blood samples from those humans are immunized with Moderna’s vaccine against BA.2.75.2. In previous studies against BA.2.75, the results were encouraging. In one mail published in New England Journal of Medicine on September 9, he and his team reported that although the levels of antibodies against the virus to BA.2.75 were four times lower than those against the original virus in people vaccinated with Moderna. , but they are still effective. However, three additional mutations of BA.2.75.2 “could make the virus less susceptible to neutralization,” he said, “but we have to test it and find out.” Results from the ongoing studies, funded by both Moderna and the National Institutes of Health, are expected in October.
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