How serious is the spread in UK of Covid variant first found in India? 

Back in December, just as millions of families in Britain were preparing to embark on much-awaited Christmas festivities, news intensified of a new Covid-19 variant that appeared to be much more transmissible than others in circulation.

The strain first identified in Kent ultimately dashed hopes of a gradual relaxation of restrictions in the new year, and was blamed for the devastating second wave of the virus that hit the UK in the winter.

Now, a week after the country reported some of the lowest infection rates since the summer of last year, the rapid spread of a family of variants first discovered in India is threatening to do much the same.

Public health officials in the UK are “anxious” about the swelling clusters of the variants, known as B.1.617, and have announced that surge testing and enhanced contact tracing will be rolled out in hotspots where the variant had been found. 

Although the UK plans to lift all coronavirus restrictions on June 21 — the next stage of lockdown easing comes on Monday with the reopening of indoor hospitality and other relaxations — the UK’s vaccine rollout may now be adapted to try and address the spike in cases.

Boris Johnson, prime minister, is due to hold a press conference addressing the issue on Friday afternoon.

But even as health officials race to adapt their plans to contain the spread of the variants, scientists and experts in the genetic make-up of viruses are still trying to puzzle through very limited data on the characteristics of the main strain that is causing concern in Britain — B.1.617.2.

One senior public health official described the current panic around the variant as “overblown”.

“This is a data free zone,” they said. “I am concerned but there’s no reason to change what we’re doing at the moment.” 

Evidence does suggest that the variant is growing much more rapidly than any other imported strains, and the UK’s own “variant of concern”, B.1.1.7, when it first emerged in December. 

There have been 1,768 sequenced cases of B.1.617.2, according to the latest data from the Covid-19 Genomics UK Consortium. Cases are clustered around Bolton, Blackburn with Darwen, Bedford and London, where the number of cases associated with other strains have continued to fall.

“If it is more transmissible, there is a possibility it will replace B.1.1.7, they’re in an arms race with one another,” the public health official said. “The question in my mind is, does that matter?”

If cases rise, but hospitalisations and deaths are kept in check, a small increase in transmissibility may not be too grave, some experts argue.

Scientists are now watching people infected with the variant like hawks to try to work out whether the variant is able to escape either natural or vaccine-induced immunity, and whether it causes more serious disease.

Underpinning nervousness about the variants is modelling released by government advisers this week that presented a sombre picture of the possible repercussions of the emergence of a more virulent or vaccine-resistant strain of Covid-19.

A variant that is as transmissible as the B.1.1.7 strain first identified in the UK, and which has some vaccine resistance, “could easily lead to another peak of double or treble the size of that seen in January 2021 if no interventions were taken”, according to the paper released by the UK’s Scientific Pandemic Influenza Group on Modelling (SPI-M). It concluded that “variants remain a major risk to the road map” out of lockdown.

But one public health official warned that the early models of this kind “should not be taken as gospel”, in part because “we’d never allow it to get that far”. “There have been catastrophically awful models which have toned down over time,” they noted. 

The good news is that a growing body of scientific study does suggest that the existing crop of vaccines are able to “neutralise” the B.1.617 family of variants, and protect against severe disease, although there may be a marginal increase in infections compared with the strain first found in Kent.

That said, most of this lab work has focused on B.1.617.1, the variant first identified in India, with limited data available specifically on B.1.617.2 which has its own unique characteristics.

A paper released by academics in India on Thursday found that recipients of the Serum Institute’s Covishield vaccine did produce antibodies when confronted with the B.1.617.1 variant, and concluded that “vaccine-induced antibodies are likely to be protective to limit the severity and mortality of the disease in vaccinated individuals”.

But as fears rise that this variant poses the biggest threat yet to a return to international travel and unfettered social interactions, attention is also turning to whether UK officials did enough to heed warning signs from India and nip the strain’s spread in the bud more quickly.

The most glaring area of inaction was the decision not to impose any limits on travel between India in the UK. The decision not to place India on the UK’s red list meant that hundreds of cases were imported last month which seeded the bigger community outbreaks happening now. India was added to the UK’s red list last week.

With surge testing already under way in those areas where the variant is more prevalent, the question now is whether other measures such as adapting the vaccine rollout will work.

Muge Cevik, a clinician and researcher in virology at Scotland’s University of St Andrews, said the idea of offering “surge vaccinations” to younger people in variant hotspots “makes a lot of sense”.

“If you look at the numbers of B.1.617.2 — it’s spreading in unvaccinated populations so you’ll be reducing transmission,” she said. Imposing harsher restrictions like localised lockdowns, however, “will need to be a last resort”. 

“Infections will not necessarily translate into hospitalisations and deaths,” she added. “Going forward we need to think about what is a proportionate response.”