An Indian Covid variant, which has been found in the UK, has been escalated to a variant of concern, Public Health England (PHE) has confirmed.
The decision to reclassify the variant is based on evidence which suggests it is at least as transmissible as a strain known as the Kent variant, PHE said.
Figures show cases of the variant in the UK have increased to 520 from 202 over the last week, and almost half of these cases are related to travel or contact with a traveller.
The cases are spread across the country, with the majority in two areas – the North West, mainly in Bolton, and London, PHE said.
The variant was was first discovered in India in March.
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PHE said there is currently “insufficient evidence” to indicate that any of the variants recently detected in India cause more severe disease or make the vaccines available any less effective.
Although cases of the strain in the UK remain relatively low, the change means PHE can escalate its response. This could include surge testing in areas where the variant is found.
There are three related variants first seen in India which have been detected in the UK. The one dubbed B.1617.2 is the one declared a variant of concern.
The two others are B1617.1 and B1617.3.
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The first report on the B1617.2 variant showed 202 cases, and the first report on the B1617.3 variant shows just five cases.
In internal PHE documents, dated to May 5 and seen by The Guardian, the risk of the variant B1617.2 to public health is “high”.
Dr Deepti Gurdasani, a clinical epidemiologist and senior lecturer at Queen Mary University of London, told The Guardian that “at the current doubling rate (B1617.2) could easily become dominant in London by the end of May or early June”.
Northern Ireland chief medical officer Dr Michael McBride said the latest news that there have been seven cases of the B1617.2 variant identified was “not entirely unexpected” and that plans were in place “for such an eventuality”.
Health experts said they “haven’t seen any hint” that currently known variants can fully evade the effectiveness of existing coronavirus vaccines.