The variant of coronavirus first identified in India was responsible for the devastating second wave of the pandemic in the country, NDTV reported on Friday, citing a government study.
The B.1.617.2 variant, now known as Delta, is “more infectious” than the Alpha strain first detected in the United Kingdom’s Kent county, said the study by scientists of the Indian SARS-CoV-2 Genomic Consortia, or INSACOG, and the National Centre for Disease Control.
The study also found that the Delta variant is 50% more contagious than the Alpha strain. While the Delta variant is present in all the states, scientists have said there is yet no evidence of its role in severity of infections and increased deaths, according to NDTV. But Delhi, Andhra Pradesh, Gujarat, Maharashtra, Odisha and Telangana were the most affected by this variant. All these states were rattled by the second surge of infections.
Significantly, the Delta variant played a big role in people contracting the coronavirus after being vaccinated. No such cases were found in connection with the Alpha strain, the study said.
The INSACOG consortium of scientists, spanning 10 laboratories across the country, is involved in sequencing genomes of coronavirus samples in different states. The study, which is still ongoing, revealed that there are more than 12,200 “variants of concern” in India. However, their presence is minuscule compared to the Delta variant, which according to the data given by the health minister last month was found in 65% of samples sequenced.
So far, genome sequencing of 29,000 coronavirus case samples have been done in India, NDTV reported. The B.1.617.1 sub-lineage was detected in 8,900 samples, while over 10,000 of these samples tested for the Delta variant.
The findings of the study came at a time when the Public Health England also announced that the Delta variant was now the dominant strain in the UK, BBC reported. Scientists believe that there may also be a higher risk of hospitalisation linked to this strain of the virus.
“With this variant now dominant across the UK, it remains vital that we all continue to exercise as much caution as possible,” said Dr Jenny Harries, chief executive of the UK Health Security Agency.
Epidemiologist Professor Neil Ferguson, a member of the UK government’s New and Emerging Respiratory Virus Threats Advisory Group, said the current “best estimate” was that the Delta variant could be “60% more transmissible” than the Alpha variant.
The data also showed that the number of Delta variant infections in schools or other educational institutions rose rapidly between April 26 and May 30, with 140 cases, reported The Guardian.
Professor Christina Pagel, director of the clinical operational research unit at the University College London, said the figure was evidence that schools were now a “major source” of transmission of the infection, especially after the government allowed secondary schools students to attend classes without wearing masks from last month.
Meanwhile, a paper by the Institute of Genomics and Integrative Biology showed that Delhi’s surge in Covid-19 cases in April was linked to the Delta variant overtaking the Alpha variant, the Hindustan Times reported.
The study, yet to peer-reviewed, said that the Delta variant increased from 5% in February to 10% in March, before overtaking the Alpha variant in April. The variant accounted for 60% of the sequenced samples in April, it said.
On Tuesday, the World Health Organization said that only the B.1.617.2 strain in India was now considered “of concern”. “It has become evident that greater public health risks are currently associated with B.1.617.2, while lower rates of transmission of other lineages have been observed,” the world health body said in its weekly epidemiological update on the coronavirus pandemic.