KATE KELLAND 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. ARE THE CONCERNS JUSTIFIED? Most scientists say yes. The new variant has rapidly become the dominant strain in cases of COVID-19 in parts of southern England,…