mcron is named as a variant of concern because mcron is named as a variant of concern because it mcroniant of concern because it has mcron is named as a variant of concern because it has concernin- concern because it has concerning properties. it has a large number of mutations and some of them have some worrying characteristics. why now there are many studies under way and a lot of work is going in south africa to characterise the variant in terms of transmissibility, in terms of severity and any impact on our countermeasures such as the use of therapeutics and vaccines. so far there is little information about there is little information about the studies are under way so we need researchers to have time to carry them out and the who will inform the public and member states when we have the information. the uk was one of the first countries to react to the new variant announcing travel restrictions on thursday. as fergus walsh reports. after months of opening up, a new coronavirus variant means travel restrictions are back. at heathrow, the last flights from south africa arrived this