Officials consider it a “variant under investigation (VUI)” rather than a “variant of concern” (VOC), which includes the Manaus, UK and South African variants.
The discovery of 77 cases of a new coronavirus variant, which first emerged in India, has caused concern among scientists and the government.
Public Health England (PHE) said 73 cases of the B.1.617 variant have been confirmed in England as well as four cases in Scotland.
Why are there concerns about the Indian coronavirus variant?
The Indian coronavirus variant is considered to have concerning epidemiological, immunological or pathogenic properties.
Paul Hunter, professor in medicine at the University of East Anglia, said the variant features two “escape mutations” – E484Q and L452R – which “are causing people to be concerned”.
“There’s laboratory evidence that both of these are escape mutations,” he told the PA news agency.
“Basically, applying what we know about other human coronaviruses would suggest that this is going to be even less controlled by vaccine. But we don’t know that for certain at the moment.”
This variant, along with others, has demonstrated the way in which Sars-CoV-2 can adapt to a human host when placed under selective pressures.
Their unique mutations are specific to the three-dimensional spikes that coat the shell of the virus. “If you think of a lock and key mechanism, the spike protein is the key and then the lock is the receptor on a human cell,” said Professor Deenan Pillay, a virologist at University College London.
Through evolution, this structure has changed shape to make it easier for the virus to bind with and penetrate our cells, as seen with the UK variant.
In some cases, as with the South Africa and India variant, it has mutated to become less recognisable to neutralising human antibodies which would normally attach to the virus’s spike protein and block its entry.
This type of mutation therefore allows Sars-CoV-2 to slip past the first line of immunological defence in people who have been vaccinated or previously infected, enabling the virus to carry on circulating.
Dr Jeffrey Barrett, director of the Covid-19 Genomics Initiative at the Wellcome Sanger Institute, said that B.1.617 should be “watched carefully” but it is “probably not at the top tier of mutations that generate the most concern”.
He told BBC Radio 4’s Today programme that the first cases of the variant were identified late last year.
“This variant has a couple of mutations that are among those that we think are important that should be watched carefully, but they’re actually probably not at the very kind of top tier of mutations, for example in the B117 – or Kent variant – or the South African variant, that generate the most concern.