Bengaluru, Dec 23: There could be a chance that a new mutated variant of the Sars-CoV-2 virus which is sweeping through the South of Britain has already made its way into Karnataka through airline passengers, according to scientists.
The so-called B1.1.7 mutated variant of the Sars-CoV-2 virus which causes Covid-19 was first identified in the United Kingdom on September 20. However, nearly three months elapsed before UK health officials identified the new variant, with the European CDC estimating increased transmissibility of up to 70%.
“It is very possible that it is already here. There have been a lot of flights between the countries since September,” said a veteran genomic scientist who did not want to be identified.
Karnataka has seen a steady number of UK origin flights in Bengaluru International Airport (BIAL) since September. According to BIAL, before the government moved to suspend flights on December 21, six flights from London were arriving at the airport weekly. Since December 1, the state has identified 3,017 passengers arriving at BIAL from the UK.
The new virus is the result of 23 distinct mutations, which according to the noted virologist Dr T Jacob John, former principal of Christian Medical College, Vellore, is better able to infect people because it better mimics a molecular pattern of a physiological substance called angiotensin which fits like a key into the “lock” of the receptor of the host human cell.
“It is not a perfect fit. But it is a better fit than the earlier variants. That is the reason why it seems to be spreading faster,” Dr John said.
However, another scientist, Adjunct Professor Vinod Scaria of the Institute of Genomics and Integrative Biology CSIR-IGIB) said there is no evidence to suggest it is less or more contagious. “The level of evidence is weak - exclusively computational and not experimental.”
Where the experts agree is the mutations have essentially resulted in a new version of the virus, although epidemiologist Dr Giridhar Babu pointed out that its level of virulence is likely the same as older variants of the virus.
At the same time, Dr Babu added that it was difficult to know if the new virus is already in Karnataka because clear evidence of this fact would have been a surge in cases. “But we have not seen a spike in numbers - there has been no widespread transmission. But if people have travelled to different places or states, the mutated virus might still seep through. The other possibility is that a cluster of new virus infections has been missed,” he said.
Another big gray area is whether people who previously had the disease face the danger of reinfection, Dr Babu explained. “The next two weeks are very important and will provide the proof,” he added.
Dr Scaria also suggested the possibility that the mutation has developed independently in India as it did in the UK, Brazil and South Africa. “But in India, we do not have too many genomic sequences to rely upon for confirmation. We only have about 4,000 sequences,” Dr Scaria said.
“The only sure way to know is when molecular studies are done in India,” Dr John added.
Those studies are now being carried out at Nimhans, with the first samples from international fliers collected and processed on Tuesday.
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