How worried should we be about a mutant strain of Coronavirus found in Denmark’s mink farms? The virus was found on its farms in June, and it emerged a few days ago that a dozen people had been infected with a strain of Covid called ‘Cluster 5’. So is this a new, more virulent strain?

Francois Balloux, a professor of genetics at University College London (UCL), has downplayed it as a story “making the rounds on Twitter.”