MUMBAI: About 59% samples of the newly identified and infectious Indian variant of SARS-CoV-2 called B.1.617 have been found in Maharashtra, although the double mutant strain is dominant only in selected districts and cities, not the entire state. Significantly, scientists have also found that both Covaxin and Covishield are able to protect against the strain.
Speaking at a webinar on “Genome sequencing of Sars-Cov-19” on Friday, Dr Sujeet Kumar Singh, director of the National Centre for Disease Control, said a total of 15,133 samples have been sequenced by the 10 INSACOG laboratories, of which 1,196 had the UK variant, 728 had the B.1.617 or Indian mutation, and 29 had the South African variant. Of the 728 samples with the Indian variant, 427 were found in Maharashtra, 124 in West Bengal, 75 in Delhi and 53 in MP, among others. However, nearly 1,200 samples had the UK mutation, of which 543 were in Punjab, followed by 124 in Delhi. Maharashtra had the UK mutation in 29 samples.
Virologist Dr Shahid Jameel, who is the chairperson of INSACOG, said that the Centre for Cellular and Molecular Biology (CCMB), Hyderabad, has found through a study of vaccinated individuals that vaccines can protect against the Indian variant. “Sera from Covishield and Covaxin are able to protect against B.1.617. Although more tests have to be done, this is some early good news coming in,” he said.
Dr Singh said that about 11% of samples have been subjected to genome sequencing. Singh said that while the UK variant is the dominant one in Punjab, it is gathering more strength in Delhi. “The UK variant that was found in 28% samples in the second week of March has increased to 50% by the last week,” he said. In Maharashtra, samples from districts in the Vidarbha region have mainly seen the mutations.
Singh, however, emphasised that the surge cannot be linked to the mutations. “Disease transmission is not only just about mutants or variants but a large number of factors such as pool of susceptible persons, immunity status of persons who are there in the community not following Covid appropriate behaviour and public health measures,” he said.
“Although some mutations are known to have immune escape properties, the preventive strategies remain the same. Appropriate masking, social distancing and sanitising remain the key measures to protect against the variants,” said Dr Jameel. Singh said that studies were also being done to understand if the mutations were impacting the clinical presentation or severity of the disease in any way. “Sentinel sites have been identified such as labs and hospitals, where we collect samples from moderate to severe patients to study if there is any correlation between the mutations and disease progression,” he said.
Dr Priya Abraham, director of the National Institute of Virology (NIV), who was also present for the webinar, addressed concerns around RT-PCR samples coming negative even though people may have clear symptoms of Covid. “Sometimes, there could be an issue of sampling, or the viral medium during transportation may lose some properties. But RT-PCR is still the most efficient in detecting Covid,” she said.