Telangana reports three cases of XBB.1.5 variant of Omicron

A scientist from a lab attached to Indian SARS-CoV-2 Genomic Consortium (INSACOG) told South First on the condition of anonymity that GISAID usually uploaded data from samples collected at least three to four weeks ago.

“Even though we have found XBB.1.5 in some southern states, it is not a matter of concern,” he said.

“We have not seen an increase in cases or hospital admissions. This could be because we already have an immune landscape that includes some exposure to XBB from July-August. But we have to keep a watch on this variant and others,” he stated.

He added the number of people who had been exposed to XBB is unknown, and the immunity might wane as well.

“As of now, there is nothing major. But it is important to watch XBB.1.5,” he added.

Meanwhile, laboratories attached to INSACOG have intensified collecting samples and genome sequencing. Different variants have been reported in the country, including south Indian states.

The variants of CH.1.1, BQ.1, and BA.2 were reported from Tamil Nadu.

XBB1.5 variant

XBB is a recombinant variant, originated by the mixing of RNAs from two separate Omicron versions simultaneously infecting the same person. XBB has been the dominant subvariant in India. XBB.1.5 is a sub-lineage of XBB.

In the US, a descendant of XBB has taken over from the previously dominating BQ.1 and BQ.1.1 sub-lineages. Currently, XBB.1.5 is spreading in New York, ahead of others. It is likely because it has greater immune evasiveness than others, especially since it undergoes more mutations

A functional @CDCgov would alert the public about the XBB.1.5 variant—which has already established dominance throughout the Northeast—and, with its big growth advantage over BQ.1.1, soon country-wide. https://t.co/tL2Y2HF2ew

— Eric Topol (@EricTopol) December 27, 2022

“Several scientists from the US have issued alerts on this variant, saying it could be of concern. Though we have not seen any traces of this variant in India, it is important to keep a track of it,” a scientist from a lab attached to INSACOG, said.

BA.2.75 replacing XBB in India?

According to INSACOG, XBB was the major variant (66.7 percent) in November 2022, while BA.2.75 variant constituted only 17.3 percent.

But in December, the XBB variant waned to 40.3 percent while BA.2.75 surged to 28.1 percent. In the last week of December, BA.2.75 variant further increased to 60 percent.

CSIR-Institute of Genomics & Integrative Biology scientist Dr Vinod Scaria said that there could be multiple explanations for the spike in the BA.2.75 variant.

“Geographical sampling bias, additional mutations of BA.2.75, which could provide it an advantage over XBB and a new variant being misclassified,” Dr Scaria tweeted. He called for more sequencing to reveal the truth.

By simple logic, this looks improbable.
There could be multiple explanations
🔘? geographical sampling bias
🔘? small no of sequences
🔘? Addl mutations in BA.2.75 which could provide advantage over XBB
🔘? a new variant misclassified

Only more sequencing can uncover the fact

— Vinod Scaria (@vinodscaria) January 3, 2023

“A larger number of samples generate percentages closer to the truth. Thus, if 10,000 samples all over the country are analysed in a given week and 7,000 of them (70%) are BA.2.75, then we can conclude that the prevalence of BA.2.75 is high,” Dr Rajeev Jayadevan, Co-Chairman of the National IMA Covid Task Force, told South First.

He added that if only 10 samples are studied and seven are BA.2.75, then the 70 percent calculation will be wrong.

Meanwhile, Covid-19 cases across the country remained stable and are not on an uptick.

Dr Rakesh Mishra, the Director of Tata Institute for Genetics and Society in Bengaluru, who works on wastewater surveillance to check the outbreak of the disease in that city, ruled out any upward trend in Covid-19 cases in the Karnataka capital.