US is closely watching South African Covid surge for clues

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South Africa has been a bellwether before. Scientists there were the first to discover the Omicron variant of the coronavirus late last year, setting off a global chain reaction. After a pandemic peak in December, cases in the country declined, but now they're on the rise again -- along with positivity rates and hospitalizations. It could spell South Africa's fifth wave.

The spike has been tied to two new sublineages of Omicron, BA.4 and BA.5, which the World Health Organization added to its monitoring list last month. They're dominating transmission in the country, accounting for almost 60% of all new Covid-19 cases by the end of April, according to South Africa's National Institute of Communicable Diseases.

South African scientists have found that BA.4 and BA.5 can evade antibodies from previous infection well enough to spark a new wave, but are less likely to do so in people vaccinated against Covid-19. Almost all South Africans are either vaccinated or have had a previous infection.

 

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