Indian Covid variant: Where in the UK has the new coronavirus strain been found?

The new variant of Covid-19 first identified in India is being closely monitored in the UK and is of “increasing concern”, prime minister Boris Johnson has said, as fears grow that its unchecked spread could delay the final easing of lockdown restrictions on 21 June.

Health secretary Matt Hancock announced in parliament on Wednesday that 2,967 cases of the Indian variant have now been confirmed in the UK - up from about 1,300 at the weekend.

As weekly Covid case rates doubled in Bolton – the town worst hit by the B1.617.2 strain – efforts to clamp down on the variant with surge testing have been stepped up in Bedford, Burnley, Leicester, Kirklees, North Tyneside, Glasgow, Moray and Hounslow in west London.

Test-and-trace chief Dr Jenny Harries insisted that the fight against the variant is not lost, despite Public Health England figures showing that 135 areas of England saw rising case rates in the week to 15 May, while Mr Johnson said there is “increasing confidence” that existing vaccines are effective against the strain.

Downing Street this week dropped a deadline to reveal whether social distancing will end next month, in an apparent hint that the planned ending of all remaining Covid rules is in huge jeopardy.

Mr Johnson has previously warned that a further coronavirus surge is likely this winter and could cause “even greater suffering” as he announced an independent public inquiry into his administration’s handling of the pandemic would commence next spring.

Where has the Indian variant been found?

Infections are particularly prevalent in the north west of England, in areas including Bolton, Greater Manchester, Blackburn with Darwen, Kirklees and Burnley.

The variant has also been detected prominently in Bedford and in Erewash in Derbyshire, Melton in Leicestershire, Selby in North Yorkshire, Newcastle and Tynemouth on Tyneside, in South Northamptonshire, South Holland, Nottingham and Sheffield, as well as in parts of London, including Tower Hamlets, Haringey, Ealing, Hounslow, Hillingdon, Harrow and Watford.

Speaking to BBC Radio 4’s Today programme, James Naismith of Oxford University said on Thursday: “I think we should view it as a country-wide problem. It will get everywhere. We keep learning this lesson, but we know that this will be the case.”

He added that local restrictions would not contain the variant’s spread. “When we tried locally having different restrictions in different regions, that didn’t really make any difference. So I don’t think thinking about a localised strategy for containment will really work.”

How many UK cases have there been so far?

The latest increase detailed by Mr Hancock saw the total rise to 2,967 confirmed cases on Wednesday, with every fresh increase adding weight to Labour’s criticism of the government over the “catastrophic misstep” of failing to slam travel restrictions on new arrivals from India last month in time to stop the spread.

B1617.2, one of three mutations of the B1617 lineage, has been designated as “under investigation” by health officials after rising to account for 20 per cent of new cases from two per cent a month ago.

Why is it such a cause for concern?

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 B1.617 lineage features two “escape mutations” – E484Q and L452R – that “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 such as the Brazilian, South African and Kent strains, 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.

Some Covid variants, including the Indian one, have mutated to become less recognisable to neutralising human antibodies that 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.