Scientists are warning that a new Coronavirus variant is the “worst” they have seen. The B.1.1.529 variant has mutations which mean it may evade immunity built up by previous Covid infection or vaccination. Cases have been detected in southern Africa and also in Hong Kong. The UK is temporarily banning flights from six countries in southern Africa – Botswana, South Africa, Namibia, Zimbabwe, Lesotho and Eswatini and placing them on its Red List – meaning any passengers who do arrive must quarantine. Clive Myrie presents BBC News at Ten reporting by medical editor Fergus Walsh, political correspondent Nick Eardley and Africa correspondent Andrew Harding.