India has registered its first six cases of the new mutant strain of the coronavirus, the Union Health Ministry said on Tuesday. The patients recently returned from the United Kingdom, where the new strain was first reported.

In a statement, the health ministry said three cases were reported from Bengaluru, two from Hyderabad and one from Pune. “All these persons have been kept in single room isolation in designated health care facilities by respective state governments,” the statement said. “Their close contacts have also been put under quarantine. Comprehensive contact tracing has been initiated for co-travellers, family contacts and others. Genome sequencing on other specimens is going on.”

So far, the new variant of the infection has been reported in Denmark, Netherlands, Australia, Italy, Sweden, France, Spain, Switzerland, Germany, Canada, Japan, Lebanon and Singapore.

The new variant

More than 50 countries, including India, have imposed travel restrictions on the UK, in an effort to prevent the spread of the new variant. India has suspended flights from the UK till December 31. Some, like France, have imposed total border closures amid widespread disruptions in trade and travel.

The new UK virus variant, which scientists have named “VUI – 202012/01”, includes a genetic mutation in the “spike” protein, which could result in coronavirus spreading more easily between people. It was first announced by Matt Hancock, the UK health secretary, on December 14, and was subsequently confirmed by Public Health England and the UK’s Covid-19 sequencing consortium. Screening back through databases of SARS-CoV-2, the virus which causes Covid-19, the first sample was taken in the county of Kent on September 20.

The variant carries 14 defining mutations including seven in the spike protein, which mediates entry of the virus into human cells. This is a relatively large number of changes compared to the many variants in circulation globally. UK Prime Minister Boris Johnson has claimed that this was as much as 70% more transmissible than previous versions. But there is currently no evidence that the variant is more likely to cause severe coronavirus infections or that it would render vaccines less effective.

Last Monday, the World Health Organization also tried to allay the concerns and said the strain could be controlled using existing measures.