New Covid-19 subvariants can reinfect Omicron-recovered patients, early studies find

A sudden rise in coronavirus cases in South Africa has scientists warning that two new subvariants can reinfect those who have recovered from a previous Omicron strain. The new variants, labelled BA.4 and BA.5, appear to be more transmissible than the already highly infectious parent strain of Omicron. But so far, these new variants do not appear to cause higher rates of serious illness.