The new Omicron sub-variant, XBB.1.5, which is spreading rapidly in the United States, has been detected in South Africa, but scientists in the African country officially the most affected by the Covid-19 pandemic say they do not fear a new "big wave" of infections.
"I don't expect a big wave of infections with hospitalizations in South Africa because of the strong immunity of the population and the previous waves of Omicron variants," South African virology star Tulio de Oliveira, who became famous for spotting the Beta and Omicron variants, said Friday on Twitter.
South Africa, which detected the first case of Omicron in late 2021, has recorded more than four million cases of the coronavirus and more than 102,500 deaths. Some 48% of the eligible population is vaccinated.
XBB.1.5, the grandson of the Omicron family, is the "most transmissible sub-variant detected to date", the World Health Organisation (WHO) warned this week.
The sub-variant was detected on Friday in the southern African country in a sample taken in late December, according to de Oliveira, but no "increase in cases, hospitalisations or deaths" has been seen at this stage.
XBB.1.5 is present in some 30 countries, notably in Europe and the United States, where it is becoming dominant. Its characteristics are not yet precisely known. But according to the first data, a booster dose with a bivalent vaccine would produce neutralising antibodies, according to the WHO.