LONDON: Health authorities in England on Friday elevated one subtype of the so-called Indian variant from under investigation to a Variant of Concern (VOC) following a rise in the number of cases in the UK and evidence of community transmission.
The B.1.617.2, classified as a Variant Under Investigation (VUI) on April 28, is now known as VOC-21APR-02 after it was found to be at least as transmissible as the so-called Kent variant, detected in England last year and the dominant variant in the UK so far.
"Cases of VOC-21APR-02 have increased to 520 from 202 over the last week and almost half the cases are related to travel or contact with a traveller," Public Health England (PHE) said.
The cases are spread across the country, however, the majority of the cases are in two areas -- the north west of England, predominantly Bolton, and London -- where the greatest transmission of the variant has been observed.
However, PHE said there is insufficient evidence to suggest if the variant is also more dangerous in that it can escape vaccine protection.
"The other characteristics of this variant are still being investigated.
There is currently insufficient evidence to indicate that any of the variants recently detected in India cause more severe disease or render the vaccines currently deployed any less effective.
PHE is carrying out laboratory testing, in collaboration with academic and international partners to better understand the impact of the mutations on the behaviour of the virus," PHE said.
It said that surge and community testing is an effective way of finding and isolating new cases of variants and will be deployed where there is evidence of community transmission.
This is in addition to comprehensive work that is already underway to trace and test all contacts of cases.
Everyone in the affected areas will be asked to get a test, even if they don't have symptoms.
If someone tests positive, they would be expected isolate to stop the spread.
UK Prime Minister Boris Johnson was asked about the development and said it needs to be handled "very carefully".
"We're doing a huge amount, obviously, to make sure that when we do find outbreaks of the Indian variant that we do surge testing, that we do door-to-door testing," he said.
The original India variant -- officially known as B.1.617 -- was first detected in October.
Last month, PHE had categorised two further subtypes to that -- B.1.617.2 and B.1.617.3.
Experts believe of the three, the variant B.1.617.2 is at least as transmissible as the so-called Kent variant, which had been detected in England at the end of last year and led to the UK's second wave surge in coronavirus infections earlier this year.
These variants are not believed to feature the E.484K mutation found in the South African variant of the virus, which could help the virus dodge a person's immune system.
The Kent, South Africa and Brazil strains have all been deemed Variants of Concern (VOCs) in the UK.
These versions, along with the India variant, have all undergone changes to their spike protein - the part of the virus which attaches to human cells.
Viruses by nature mutate, producing different versions of themselves.
Most of these mutations are insignificant but some can make the virus more contagious and harder to vaccinate against.
The Indian variant is believed to be largely behind the current surge in infections in India's ongoing severe second wave of the pandemic.