Sequencing data, released in a timely way, can also help epidemiologists understand infections and mortality trends
India’s woeful tracking of coronavirus variants could jeopardize the world’s fight against covid-19, several experts warned, even as a variant first found here spreads its claws overseas. With less than 0.1% of all covid-positive samples sent for genetic studies, India ranks behind over 100 countries, despite having millions of more cases. The Centre’s own target of 5%, set in December, remains a far cry.
The UK has sampled roughly 9% of its cases for genome sequencing, and is now finding the variant B.1.617.2 in up to three in four samples. Germany and the US sampled 3% and 1.5%, respectively, shows data compiled by Johns Hopkins University. Among the 10 countries with the highest covid-19 caseload, India fares better than only Russia and Turkey.
Genome sequencing studies the structure of a virus to generate vital and timely insights about mutations that can help policymakers anticipate the course of the pandemic. Not doing enough in time can let variants leak outside the origin country and delay research into how fast they transmit and which vaccines could counter them, scientists say. It can also deprive disease trackers of crucial data.
India first detected the B.1.617 variant, which transmits faster than the original variant, in October 2020. Only two months later did the Centre ask 10 labs to do genome sequencing more systematically, as part of the Indian SARS-CoV-2 Genomic Consortia (INSACOG). So far, 25,739 covid-positive samples were sent for genome sequencing, according to a 24 May statement by health minister Harsh Vardhan. Around 20% had B.1.617, now classified as a “variant of concern" by the World Health Organization, with cases in 53 countries.
Genome sequencing is not very expensive, but needs more funding, staffing, and facilities, said Jacob John, a professor at Christian Medical College, Vellore. “We also need a plan combining clinical, public health, and research priorities to create a pipeline of well-annotated samples, carefully selected to answer key questions," he said. “For this whole exercise to be relevant, we need sequencing to happen rapidly, within days or hours, and at a quality that meets global standards."
The Centre said recently that it would add 17 labs to INSACOG.
“High genome sequencing in the UK helped local governments adapt their public health strategies, such as lockdowns and vaccinations, to variants that were more infectious and spreading faster," said Prabhat Jha, a professor of epidemiology at the University of Toronto. But in India, variants are likely quite widespread but mostly unknown, so states have little information to plan strategies to reduce community transmission.
Sequencing data, released in a timely way, can also help epidemiologists understand infections and mortality trends, said Murad Banaji, a mathematician at Middlesex University. It could help cities and states anticipate and prepare for surges and inform vaccination strategy, he said.
“It’s a real shame that we are often forced to speculate when the data could be gathered and shared," Banaji added.