(Bloomberg) -- South Africa will offer additional Covid-19 booster vaccines to all residents older than 18 years after detecting the omicron sub-variant XBB.1.5, which appears to be more transmissible than the original strain.

The details of the vaccinations will be announced in the next few days, even as “the immunity of South Africans from vaccination and natural immunity is still very strong,” Health Minister Joe Phaahla said in an online briefing on Tuesday. 

The potential impact of the sub-variant, which was first detected in the US in October and nicknamed the “kraken variant” for its ability to spread, is unclear. So far there is no indication that the strain is causing more severe symptoms and South Africa hasn’t experienced a major jump in Covid cases, related hospitalizations or deaths, the minister said. 

 

While wastewater from within South Africa shows low levels of the coronavirus at the moment, the situation is being closely monitored, said Michelle Groome, head of public health surveillance and response at the National Institute for Communicable Diseases. Vigilance is also necessary as many schools reopen this week after the Christmas holidays. 

The discovery of XBB.1.5 in South Africa came from a single, random sample taken on Dec. 27 and was identified over the weekend in gene sequencing carried out by researchers at Stellenbosch University. 

Samples of wastewater from US flights, as well as from China where the relaxation of Covid-19 restrictions has lead to a surge in cases, will also be initiated, Phaahla said.

“There is no need to impose any travel restrictions on any country, including The People’s Republic of China,” he said. “We also do not need any restrictions internally in our own country.”

Additional Covid-19 vaccines are expected to be offered in South Africa this month, although bivalent booster doses aren’t yet registered in the country and so there are no plans to buy these shots at this stage. 

The country has about 8 million doses of the Pfizer Inc. and BioNtech SE’s inoculation and 10 million of Johnson & Johnson’s shot, said Lesley Bamford, a specialist at the health department. People are able to choose either for their additional booster, she said. 

(Updates with vaccine stocks in last paragraph)

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