If there’s one thing we’ve learned from the Covid-19 pandemic, it’s that evolution doesn’t have to be a long process that takes thousands or millions of years. It is fast and non-stop.
Recently, the US Centers for Disease Control and Prevention (CDC) reported that a new subtype of Ómicron, BA.5, invaded South Africa in the spring and finally dominated the United States after being first detected in March.
No ‘party’, so to speak: On the same day, the World Health Organization (WHO) released a video on social media about a new variant emerging in India. A.2.75 – nicknamed ‘Centarus’ on social media – has already arrived in the US, the CDC confirmed to ‘Fortune’ magazine, with the first two cases identified on June 14. However, it is already in place in about 10 countries, said Soumya Swaminathan, WHO’s chief scientist. It has not yet been declared a variant of concern or a variant of interest, and it is too early to assess the spread, severity and potential for immune evasion, he added.
.@DrSoumya Explains what we know about the origin of possible omicron subvariance [referred as BA.2.75] ⬇️#Covid-19 pic.twitter.com/Eoinq7hEux
– World Health Organization (WHO) (@WHO) July 5, 2022
But there are experts who are already raising red flags – especially the additional changes compared to Ómicron (up to 9). Neither mutation is particularly worrisome, “but it’s another thing to appear together all at once,” warned Tom Peacock, a virologist in the Department of Infectious Diseases at Imperial College London, England.
Observant minded – BA.2.75 should be kept a close eye – lots of spike mutations, possible second generation variation, apparent rapid growth and wide geographical spread…https://t.co/sY0edKoQHX
— Tom Peacock (@PeacockFlu) June 30, 2022
BA.2.75 is “something we should all be concerned about,” said Bruce Walker, director of the Ragan Institute at MGH, MIT and Harvard, which focuses on eradicating the disease. The new variant “gives us insight into what the virus is capable of in terms of mutation. Here again is a virus that bears a resemblance to the original Ómicron variant, but with minor amino acid changes that make it immune-evasive. What all these variations show us is that the virus is not even close to exploring all available evolutionary space.”
It remains to be seen whether BA.2.75 will make a global wave or fail quickly – like the lambda and mu types – explained Stuart Ray, a professor at Johns Hopkins Medicine in the US. “There are variations that appear occasionally and have characteristics that worry us,” he said. “But until we see them ‘competing’ in different settings, it’s hard to know what they mean to us.”
These variants were once overlooked but are now gaining attention as a result of “intense surveillance and increased attention to sequencing,” said Daniel Kuritzkes, MD, chief of the Division of Infectious Diseases at Brigham and Women’s Hospital and a professor of medicine at Harvard. “We saw all kinds of variations in the Omicron family,” he said. “We really need to see a significant increase in the number of cases in many places to know if this is really a major variable of concern.”
However, ‘Centaurus’ is not the only Covid-19 subtype that has attracted attention recently: there is growing interest in BA.5.3.1, also known as ‘Bad Net’, and is a ‘spin-off’ of BA. .5 sub-variant is present on the planet. In Germany, it has been increasing since the end of May, accounting for almost 80% of BA.5 cases. BA.5.3.1 has also been detected in the United States, a CDC spokeswoman said, but in less than 5% of cases.
Another relative of the BA.5 that has hit the radar: the BA.5.1, which has been circulating in the UK. “Variants and subtypes are fragmenting quickly. There are not one or two, but hundreds of variants and subtypes. Ómicron hit the scene in early November 2021. Nothing has been the same since.
Each of its successful variants is a spin-off of the Ómicron: ‘Stealth Omicron’, BA.2, BA.2.12.1, BA.4 or BA.5. A successor to Kuritzkes is interesting. “We continue to see omicron derivatives rather than something completely different emerging,” he pointed out. “Before Omicron, everything that appeared was very different from what was in circulation. Delta didn’t come from beta; beta didn’t come from alpha.
“The virus may have finally found an evolutionary point where it can do very well, and it mutates, messing around the edges to gain small advantages,” the expert explained. Some point to Omicron’s mild symptoms and obvious upper respiratory tract predilections compared to the original variant, which carries a higher risk of pneumonia and death.
Scientists suggest that less severe disease and greater transmission may actually be a good thing. But it’s still too late to draw that conclusion, Kuritzkes cautioned. Time will tell if the emerging sub-variants are potential threats or distractions.
