Experts concerned over new Omicron subvariant BA.2.86

PUNE: Experts have raised concerns over the emergence of a new Omicron subvariant - BA.2.86 - alongside a slight uptick in active Covid-19 cases recently in some parts in India, including Maharashtra.
Active Covid cases in the state went up to 127 on Tuesday. The active case count was 116 on Monday.
Dr Rajesh Karyakarte, Maharashtra's coordinator for genome sequencing and a senior scientist with BJ Medical College, told TOI, "XBB.1.16 and XBB.2.3 are still the predominant variants.But the genomic makeup of the new BA.2.86 subvariant is of concern. It exhibits an unprecedented evolutionary leap with approximately 34 new mutations in comparison to Omicron subvariant BA.2, which caused the third wave in India, along with BA.1."
He said in comparison to XBB.1.5 (Covid vaccine strain used in the US), BA.2.86 has 36 different mutations.
"Compared to the index or the Wuhan virus, responsible for the first wave of Covid, the BA.2.86 variant displays 58 novel mutations. The new mutations found in BA.2.86 exhibit distinct characteristics, including enhanced binding to ACE2 receptors and heightened potential for immune evasion when compared with the XBB.1.16 and XBB.2.3 variants," Karyakarte said.
He said India had the best vaccination in the world and a chunk of the population earlier got infected with XBB.1.16 and XBB.2.3.
These could provide some immunity against this new subvariant, he said.
"But a close watch should still be kept on BA.2.86 because it is vastly different from all the other recent Omicron sublineages," Dr Karyakarte added.
Dr Vipin M Vashishtha, member, WHO's Vaccine Safety Net, said, "The new subvariant has been so far detected in limited sequences in Denmark, Israel, US and the UK. The problem is that the rate of sequencing has gone down tremendously even in those countries that were earlier doing excellent sequencing, and more so in India. This means that even if this subvariant has entered a wider geographical area, it may still be undetected."
"The cases of this new subvariant found in the four countries are independent ones, unrelated to one another, pointing to some level of community transmission," Vashishtha added.
He said the current number of active or new Covid cases in India did not point to a surge, apart from some states like Maharashtra, where there had been slight increase on a few days. So, he said, it was still too early to call it a surge.
"If BA.2.86 enters India, the population's past immunity from vaccination or infection may not provide full protection as close to 17 or more mutations in this subvariant are absolutely new," said Vashishtha.