Coronavirus variants first detected in India risk becoming the UK’s second most dominant within weeks, experts have warned after total cases rose to 400.
Public Health England (PHE) said on Thursday that there was “no evidence of widespread community transmission or that these variants cause more severe disease or render the vaccines currently deployed any less effective”.
But other scientists said it was worrying that the UK’s detected cases appear to be increasing rapidly despite England still being under social-distancing restrictions. India was placed on England’s travel “red list” from 23 April, restricting arrivals to citizens and residents who must quarantine in a hotel.
India has been plunged into a healthcare crisis due to a surge in cases that may in part be due to the variant. B.1.617, first detected in India, is a “variant under investigation” in the UK that has raised concerns because it contains two “escape” mutations that may help it to evade the body’s immune responses.
An extra 61 confirmed cases of B.1.617 were recorded in the UK in the week up to 28 April, bringing the total to 193 cases, PHE data shows.
It also reports 202 cases of a closely related variant called B.1.617.2 – which lacks one of the escape mutations – and five cases of a closely related variant called B.1.617.3. These variants were reported for the first time on Thursday and have each been classified as a “variant under investigation”.
A rise has also been seen in data from the Covid-19 Genomics UK Consortium (COG-UK) which relates to specimens rather than cases, and may contain duplicates. While two specimens in the UK containing a form of the India variant were collected in February, the total has now reached 482.
Prof Christina Pagel, the director of the clinical operational research unit at University College London and a member of the Independent Sage group of experts, said the situation was worrying.
“The latest data on the B.1.617 variant is certainly concerning – it is rapidly on its way to becoming the most commonly detected variant other than the dominant ‘Kent’ variant in the space of just a few weeks,” she said.
Her own analysis based on COG-UK data revealed that while 16 specimens collected in England in the week ending 20 March contained B.1.617 or its close relatives, this rose to 179 for specimens collected in the week ending 17 April.
Pagel said it was important to establish whether infections of the India variants coming from overseas are over-represented in the data, noting the UK automatically sequences positive cases of all incoming travellers but only some cases in the community.
Paul Hunter, a professor in medicine at the University of East Anglia, cautioned that more information is needed, including data about how severe the disease is compared with previous variants in both immunised and non-immunised individuals. But he agreed the India variants could become a major challenge for the UK.
“That we have a new variant that is increasing so rapidly, even during a period when we are still in a pretty strict lockdown and have more than 50% of the UK population with at least one immunisation, is very depressing and suggests that as we come out of lockdown this variant could accelerate even more rapidly,” he said.
Dr Susan Hopkins, Covid-19 strategic response director at PHE, said: “Case numbers of both new variants under investigation remain low and investigations continue into links with international travel. There is no evidence of widespread community transmission or that these variants cause more severe disease or render the vaccines currently deployed any less effective.”