The WHO warned that preliminary evidence suggests the variant has an increased risk of reinfection and may spread more rapidly than other strains.
A number of pharmaceutical firms have said they are working to adapt their vaccines in light of the emergence of Omicron.
Health Secretary Sajid Javid said there is “huge international concern” surrounding the strain after banning flights from South Africa, Botswana, Lesotho, Eswatini, Zimbabwe and Namibia to limit its spread.
Mr Javid told MPs there are concerns the variant may be more transmissible, make existing vaccines less effective, and it may hinder one of the UK’s Covid treatments, Ronapreve.
Ministers were facing calls to go further to prevent a wave of the new variant arriving in Britain while a Delta surge is ongoing, as Belgium became the first EU country to announce a case.
Professor John Edmunds, who advises the Government as part of the Scientific Advisory Group for Emergencies (Sage), warned that could create a…