Explainer - The new coronavirus variant in Britain: How worrying is it?

FILE PHOTO: People walk past the closed entrance of the Eurostar terminal at Brussels South railway station after Britain's European neighbors began closing their doors to travelers from the United Kingdom amid alarm about a rapidly spreading strain of coronavirus, in Brussels, Belgium December 21, 2020. REUTERS/Yves Herman

LONDON (Reuters) - A new variant of the pandemic SARS-CoV-2 coronavirus is spreading rapidly in Britain and prompting high levels of concern among its European neighbours, some of which have cut transport links.

The strain, referred to by some experts as the B.1.1.7 lineage, is not the first new variant of the pandemic virus to emerge, but is said to be up to 70% more transmissible than the previously dominant strain in the United Kingdom.