Three sub-lineages of Delta variant found in 298 samples in city

Three sub-lineages of the Delta variant of the novel coronavirus, including AY.4 and AY.12, have been found in the 298 samples of Bengaluru residents genomically sequenced in the last three weeks.

Members of the state genomic surveillance committee said these lineages must be closely watched, considering the Covid outbreak in countries like Israel (where most cases were AY.12). Researchers have projected that a new variant of the virus could be a triggering factor in the third Covid wave.

As per data provided by Strand Life Sciences which did the sequencing, the Delta-derived variants found in the samples include AY.1 (Delta plus), AY.12, AY.2, AY.3, AY.4, AY.6, and B.1.617.2 (baseline Delta).

State nodal officer for covid-19 testing Dr C N Manjunath said the third wave could be less intense if the virus strain did not change. “But if the virus strain changes between now and October-November, the magnitude of the third wave would be difficult to predict,” Dr Manjunath said.

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A source who did not want to be named said the data was still being uploaded to INSACOG (Indian SARS-CoV-2 Genomics Consortium). “Only after (the process is over) does the state can announce the findings,” he added.

Out of the 320 sequenced Covid samples, he said authorities were seeing a growing trend of patients who were AY.4 and AY.12 positive. “No differences had been seen in children and adults,” he added.

“The major concern they noticed is the numerous protein mutations happened in the end terminal of the spike protein.” If a new variant comes up in the coming months, it may happen in this region of the spike protein. “We’re closely watching if there’s a potential for vaccine-escape mutation which may lead to future outbreaks,” he said.

Bruhat Bengaluru Mahanagara Palike (BBMP) Special Commissioner (Health) D Randeep said two labs — Strand Life Sciences and Molecular Solutions — did the sequencing.

“Out of the 418 samples sequenced by Molecular Solutions that are not older than three or four weeks, they found 38 samples with the AY.6 Delta lineage variant, four samples with AY.4, three with AY.3, and 268 with the baseline Delta. In 87 other samples, there was a failure to amplify or sequence the sample. Strand has also told us that they’re watching out for any new mutant variants,” he said.