The Omicron BA.2 sub-variant of Covid-19 appears to be more infectious than the original BA.1 sub-variant, but does not cause more severe disease, the head of Africa's top public health body said, citing data from South Africa.

"South Africa is reporting that it is more transmissible than the BA.1 variant, but interestingly and very encouragingly the severity seems to be the same," Africa Centres for Disease Control and Prevention head Dr John Nkengasong said, according to Reuters.