Two new variants linked to the Covid-19 strain first found in India have been identified as the number of cases linked to the country have doubled to 400 in a week.
Public Health England (PHE) said the two variants share the same lineage – a distinct fingerprint of genetic mutations – as the Indian variant known as B.1.617.
The two variants are designated as “variants under investigation” (VUI) – the same as B.1.617 – rather than “variants of concern” (VOC), such as those first identified in Kent, Manaus in Brazil and South Africa.
PHE said it has identified 202 cases of one of the variants and five cases of the other that are “geographically dispersed in England”.
A total of 193 cases of the original B.1.617 variant linked to India have now been identified in the UK, the latest PHE data shows – up by 61 since its last update a week ago.
PHE said it has been monitoring the variants since early April and has increased lab testing “to better understand the impact of the mutations on the behaviour of the virus”.
Officials said there is currently no evidence to suggest that disease from the newly identified variant is more serious than previous ones, nor is there current evidence to suggest vaccines are less likely to work against it.
In India, Covid-19 rates are soaring, thanks in part to infectious new variants.
Prime minister Boris Johnson said the government continues to “work closely” with its Indian counterparts to “determine what further help they may need”, as the devastating surge of new infections continues to tear through the country.
There are a total of 226,635 cases of the Kent variant, known as B.1.1.7, in the UK, PHE figures show.
There are four variants of concern and nine variants under investigation which have been identified in the UK.
At the Downing Street press conference on Wednesday, health secretary Matt Hancock said concern around the impact new variants could have on the UK vaccine programme was behind the policy decisions on tight border controls.
Professor Jonathan Van-Tam, deputy chief medical officer for England, said it was difficult to assess how new coronavirus variants would impact vaccines being rolled out in the UK but he hoped the inoculations would continue to protect against severe illness.