The boss of the World Health Organisation has warned there are two new sub-variants of Covid emerging in South Africa that are even more infectious, are likely to make vaccines less effective and have two new symptoms.
The WHO chief Tedros Adhanom Ghebreyesus said the new viruses are subvariants of Omicron, which emerged in South Africa last year and have now swept the world in a third wave of the coronavirus pandemic.
The new variants are BA.4 and BA.5, and are believed to be responsible for a new surge in cases in South Africa, among people who have already had Omicron.
