PUNE: Omicron is now the dominant SARS-CoV-2 variant here, fast replacing Delta in little over a month, an analysis of 1,769 samples sequenced at the Indian Institute of Science Education and Research, Pune, and the National Chemical Laboratory has revealed.
Genomic sequencing at the two institutes, between November 28 and January 8, found that Omicron was in just 1% of samples from November 28 to December 4. But in samples analysed between January 2 and January 8, the variant was in 83% of samples.
Scientists from the two institutes said the finding indicated that the new variant has been spreading in the community. The data also suggested that most of the Covid-19 cases being reported currently could be attributed to Omicron, Dr Krishanpal Karmodiya, professor of biology at IISER, told TOI.
Omicron present in 83% of samples sequenced in city
Delta, meanwhile, seems to have lost its hold on Pune, with just 0. 004% of samples sequenced in the latest week (January 2-8) reporting the variant and 14% reporting Delta sub-lineages.
Experts said though Omicron is seeing rapid spread, a silver lining is that it has replaced the more virulent Delta variant, which was associated with severe Covid and a large number of hospitalisations during the second wave.
The scientists, however, said the public needs to be cautious. “Omicron has exponential growth advantage which facilitates high transmission. This property of the virus threatens to offset any relief due to less severe disease caused by this variant,” Dr Dhanasekaran Shanmugam, senior principal scientist and coprincipal investigator on the project at NCL, told TOI.
“Therefore, regardless of the variant, Delta or Omicron, Covid-appropriate behavior will help in getting through the current wave,” he said.
Dr Karmodiya from IISER said, “Although there is a reduced risk of severity, since there are many confounding variables that influence the course of disease, it makes it difficult to predict outcomes. ”
Dr Anu Raghunathan, senior principal scientist and principal investigator at the NCL said, “The Omicron variant is concerning mainly for antibody countermeasure efficacy because of the number of mutations in the spike protein. The worry is that antibodies in clinical use may lose efficacy against the B. 1. 1. 529 Omicron variant. ”
She added, “When transmission rates are high and there is an inevitable lag between infection and hospitalisation, infection among large numbers in the population eventually run the risk of undesirable outcomes. In the end it’s not just the virus, but also the host and the environment that dictate outcomes. ”
Dr Sanjay Pujari, member of the national Covid task force, said, “Omicron seems to cause mild illness in a majority of patients but it can still cause severe Covid in the unvaccinated, partially vaccinated or vulnerable population. ”
Researchers at IISER Pune and CSIR-NCL have sequenced samples through generous funding from Rockefeller Foundation and also supported by CSIR-NCL, the Villoo Poonawalla Foundation and the Jankidevi Bajaj Gram Vikas Sanstha.
