Since the Omicron epidemic in 2021, SARS-CoV-2 has evolved at a slower, more predictable pace.new variation of interest It came and went, but nothing matched Omicron’s thirty-something mutations and its ferocious growth. Then, about two weeks ago, a variant derived from BA.2 emerged. 34 mutations That spike protein was an evolutionary leap in viruses and certainly looked a lot like omicron. My question is: Could this also spread as quickly and widely as Omicron?
This new variant, called BA.2.86, is currently being detected in at least the following locations: 15 cases in 6 countries, including Israel, Denmark, South Africa and the United States. This is just a gradual increase in new infected people, not a flood, so you can rest assured to some extent. But because surveillance for the new coronavirus is no longer a priority, research laboratories around the world are also sequencing about 1 percent of what they did two years ago, says virologist Thomas Peacock of the Purbright Institute. . The less oversight scientists have, the more likely it is that variants will spread out of sight, and the longer it will take to understand the potential of BA.2.86.
Peacock said he plans to closely follow the data from Denmark over the next week or two. The country still has a relatively robust SARS-CoV-2 sequence analysis, and he has already detected BA.2.86, so we can now monitor in real time whether the numbers increase. Until the future of BA.2.86 becomes clear, he still sees three scenarios.
The worst but least likely scenario is another Omicron-like riot around the world. BA.2.86 doesn’t seem to be growing as explosively. “If it had been so fast, we probably would have known by now,” Peacock said, noting that Omicron’s rapid growth, by contrast, took only three or four days to become apparent. did.
Scientists are still not entirely willing to leave Omicron redux on record, even if patchy virus surveillance means no one has the full picture. Back in 2021, South Africa realized that Omicron was causing a major wave of novel coronavirus, allowing South African scientists to warn the rest of the world. But if BA.2.86 is causing ripples in areas where the virus isn’t even sequenced or tested much, no one knows.
But even in this scenario our herd immunity will be a buffer against the virus. BA.2.86 is theoretically believed to have an Omicron-like ability to cause reinfection. Preliminary analysis of the mutation Jesse Bloom, a virologist at Fred Hutchinson Cancer Center in Washington, said, but added that there is a big difference between 2021 and now. “At the time of the Omicron wave, there were still a lot of people who had never been vaccinated or had SARS-CoV-2. “Today, the vast majority of people worldwide are either infected with SARS-CoV-2 or vaccinated, or are often both infected and vaccinated multiple times. I think variants will have a very hard time spreading, just like Omicron.”
A second, more likely possibility is that BA.2.86 will be similar to other post-Omicron variants. That is, it is infectious enough to overtake previous variants, but not sufficiently infectious to trigger a large new surge. Since his original Omicron variant i.e. BA.1 took over, US has cycled his BA.2, BA.2.12.1, BA.5, BQ.1, XBB.1.5 one after another . It seems like you know just a little bit, but that’s because it didn’t reach the same level of notoriety as the original.Vaccine makers are tracking vaccines to keep up to date with COVID-19 vaccinations, but the World Health Organization I don’t think anything deserves a new Greek letter.
However, as BA.2.86 continues to circulate, mutations that confer new benefits may be detected. In fact, his XBB.1.5, which emerged earlier this year, leveled up in this way. Peacock said that when the predecessor of XBB.1.5 was first seen in Singapore, it wasn’t a very successful variant. The spike protein bound weakly to receptors on human cells. It then acquired an additional mutation in the spike protein that compensated for the loss of binding, later changing to the predominant his XBB.1.5. Descendants of BA.2.86 may eventually become more contagious than current variants.
A third scenario is that BA.2.86 suddenly disappears. Scientists now believe that highly mutated variants such as BA.2.86 are likely the product of chronic infection in immunocompromised patients. In these infections, the virus stays in the body for longer periods of time and tries new ways to evade the immune system. Ultimately, mutations may occur that make the spike protein less recognizable to antibodies, but the same mutations may also impair spike protein function, thereby reducing the ability of the virus to spread from person to person. There is
“Such variants have been seen in the last few years,” Bloom said. “Often, one sample is found and that’s it. Or multiple samples, all found in the same place.” Yes, but it’s unclear if it can overtake existing variants. To do so, BA.2.86 must evade antibodies while maintaining its inherent infectivity. Otherwise, there may be cases of infected people here and there, but the variant won’t actually spread, Bloom said. In other words, the situation in BA.2.86 is basically the status quo.
In the coming weeks it will become clear which future we are living in. We’ll find out soon enough when the number of BA.2.86 infections starts to rise in a more alarming way. However, unless the distribution of variants increases dramatically each week, it is unlikely that BA.2.86 will actually become a variant of concern.