One virus variant dominates samples in Bengaluru: Nimhans | Bengaluru News – Times of India
BENGALURU: In a paper published in scientific journal MedRxiv, researchers from Nimhans say there are four major SARS-CoV-2 variants circulating in Bengaluru and of them, the B.1.36 variant has the highest prevalence. The variant was seen in 45% of the swab samples which Nimhans subjected to genomic sequencing recently.
Nimhans received 183 Covid positive samples, including 75 from international travellers who arrived in Karnataka and had tested positive between December 22, 2020 and January 31, 2021. The remaining samples also included those from two clusters in Bengaluru.
Of the 103 samples Nimhans processed, the B.1.36 variant was detected in 43 samples (45%), followed by 25.2% samples showing B.1, another variant. A variant called B.1.74 was seen in 4.9% of the samples and B.1.468 variant in 3.9%.
“Of particular concern are those variants that carry mutations/amino acid changes conferring higher transmission, more severe disease, re-infection, and immune escape. These can broadly be classified as variants of concern (VOCs),” the study says.
However, speaking to TOI, renowned virologist Dr V Ravi, who spearheaded the study, says B.1.36 cannot be called a variant yet as its significance is yet to be studied.
Dr Ravi, also the nodal officer for genomic sequencing of SARS-CoV-2, said B.1.36 is not a local variant since international passengers too had it. “We had conducted a similar study during the lockdown in 2020 and at that time, B.1.36 was seen in 2% of samples,” he said. “Now it is up to 45% of the studied samples.”
More research needed
Dr Ravi added that to prove that it is a ‘variant of concern’, further research needs to be conducted. “We do not know the significance of the variant,” he said. “This requires further research for which we do not have the facilities. It requires a lot of experiments in cell culture studies and complete tracing of all primary and secondary contacts of the people who gave the samples. We do not have that kind of information.”
The variant is also seen in Telangana, Andhra Pradesh and Kerala, but no studies have been conducted on whether the variant contributes to extra spread or not, Dr Ravi said.
He said the study focused on analysing the introduction and spread of new variants in Bengaluru. “So far, the UK variant is restricted only to those who had travelled abroad. We came across the increased prevalence of B.1.36 variant while researching the UK variant,” he said.
The central government had recently launched Indian SARS-CoV-2 Genomic Consortia (INSACOG) of 10 prominent labs in the country, to study if there is a new Indian variant of the virus. Nimhans is one among 10 chosen institutes.
Researchers of the department of neurovirology say “the study data supports the use of concentrated and continued genomic surveillance of SARS-CoV-2 to direct public health measures and suggests revisions to vaccines, and serve as an early warning to prepare for a surge in Covid-19 cases.”