Dr. N K Arora, co-chair, Indian SARS-CoV-2 Genomics Consortium (INSACOG) in a recent interview said that delta variant of Covid-19 is 40 to 60 per cent more transmissible than the Alpha variant.
B.1.617.2, a variant of COVID-19 is known as the Delta variant. It was first identified in October 2020 in India and was primarily responsible for the second wave in the country, today accounting for over 80 percent of new Covid-19 cases. It emerged in Maharashtra and travelled northwards along the western states of the country before entering the central and the eastern states.
The Delta variant has mutations in its spike protein, which helps it bind to the ACE2 receptors present on the surface of the cells more firmly, making it more transmissible and capable of evading the body’s immunity. The variant has already spread to more than 80 countries, including the UK, the USA, Singapore among others.
The Indian SARS-CoV-2 Genomics Consortium (INSACOG), established in December 2020, was a consortium of 10 laboratories. Recently 18 more laboratories became part of it.
“The idea is to have a strong network of laboratories to do genomic surveillance of the SARS-CoV-2 and correlate whole genomics sequencing (WGS) data with clinical and epidemiological data to see whether or not a variant is more transmissible, causes more severe disease, escaping immunity or causing breakthrough infections, affecting vaccine efficacy, and diagnosed by current diagnostic tests,” Dr. Arora said.
Talking about the functioning of INSACOG Dr. Arora added that the entire country has been divided into geographical regions and each lab is given the responsibility of one region. “The current capacity of the country is to sequence over 50,000 samples per month; earlier it was approximately 30,000 samples,” he said.
Dr. Arora also said that the Delta Plus variant is still under study for its transmissibility, virulence, and vaccine escape characteristics.
The Delta Plus variant, AY.1 and AY.2, has so far been detected in 55-60 cases across 11 states, including Maharashtra, Tamil Nadu, and Madhya Pradesh. AY.1 is also found in countries like Nepal, Portugal, Switzerland, Poland, Japan but AY.2 is less prevalent.
He reinforced the fact that current vaccines are effective against Delta Variant as per the studies undertaken by ICMR on the issue.
The Possibility of a Future Wave-
A virus begins infecting a part of the population, which is most susceptible and also exposed to the infection. It diminishes after it successfully infects a large proportion of the population and strikes back when the immunity developed in the people post-natural infection fades. The cases may go up if a new, more infectious variant comes. “Next wave will be driven by a virus variant to which a significant proportion of the population is susceptible,” Arora said. “The second wave is still going on. Any future waves will be controlled and delayed if more and more people get vaccinated and most importantly, people follow COVID-Appropriate Behaviour effectively, especially till a substantial part of our population gets vaccinated.”