Covid: Delta variant 40-60% more transmissible than Alpha, says govt expert

The Delta variant, first detected in India is around 40 to 60 per cent more transmissible than the Alpha variant found first in the UK and the current vaccines are effective against the mutation, N K Arora, co-chair of the Indian SARS-CoV-2 Genomics Consortium.

The Delta-plus variant is still being studied for its transmissibility, virulence, and vaccine escape characteristics and, a health ministry press statement quoting Arora said.

“The cases may go up if a new, more infectious variant comes. In other words, the next wave will be driven by a virus variant to which a significant proportion of the population is susceptible,” Arora said.

The Delta Plus variants—AY.1 and AY.2—have so far been detected in 55-60 cases across 11 states, including Maharashtra, Tamil Nadu, and Madhya Pradesh.

He added however, that any future waves will be controlled and delayed if more people get vaccinated and follow COVID-Appropriate Behaviour effectively.

He said that it was difficult to say that the disease caused due to Delta Variant is more severe because the age profile and the deaths during the second wave in India were quite similar to that seen during the first wave.

INSACOG has expanded its network from 10 laboratories in the beginning of the pandemic to 28 labs now and a capacity to sequence 50,000 samples per month from 30,000 earlier.

Arora said that the entire country has been divided into geographical regions and each lab is given the responsibility of one particular region.

“We have formed 180-190 clusters with around four districts in each cluster. Regular random swab samples and samples of patients who develop severe illness, vaccine breakthrough infections, and other atypical clinical presentations, are collected and sent to regional laboratories for sequencing,” he said.

Talking about the Delta variant first identified in October 2020 in India, Arora said it was primarily responsible for the second wave in the country, accounting for over 80 percent of new Covid-19 cases.

The variant emerged in Maharashtra and travelled northwards along the western states of the country before entering the central and the eastern states. “Though there is a significant dip in the number of cases in most parts of the country, some regions are witnessing a high-test positivity rate particularly in the north-eastern parts of the country and several districts in the southern states, most of these cases could be due to the Delta variant," Arora added.