South African scientists have detected a new COVID-19 variant that is posing a "major threat" to efforts to curb the virus, officials announced at a press conference on Thursday.

Health Minister Joe Phaahla said the variant, called B.1.1.529, is behind an "exponential" increase in reported cases in the country.

"[It] is now a variant of serious concern which driving the spike in numbers," said Phaahla.

Virologists have detected almost 100 cases linked to the variant in the country.

Last week, South Africa saw about 200 new confirmed coronavirus infections per day, then daily new cases increased to more than 1,200 on Wednesday and climbed to 2,465 on Thursday.

What do we know about the variant?

B.1.1.529 has multiple mutations and it could help it evade the body's immune response and make it more transmissible, scientists warned.

"Although the data are limited, our experts are working overtime with all the established surveillance systems to understand the new variant and what the potential implications could be," said Adrian Puren, acting executive director of South Africa's National Institute for Communicable Diseases.

While the delta variant has two mutations and the beta variant has three — the B.1.1.529 variant has at least 32 spike protein mutations.

Christina Pagel, the director of Clinical Operational Research Unit at University College London (UCL) and a leading UK expert on COVID-19, called the new variant "extremely worrying."

Younger people appear to be contracting and spreading the newly identified variant, but the next weeks will be key in determining how severe the variant is, scientists said.

The new variant has already been detected in South Africa's most populated province, Gauteng, where Johannesburg and Pretoria are located.

Francois Balloux, director of the UCL Genetics Institute, said in a statement to the Science Media Centre the variant could be present in other parts of Africa.

"For the time being, it should be closely monitored and analyzed, but there is no reason to get overly concerned, unless it starts going up in frequency in the near future," he told the SMC.

Up to 90% of new cases in the Gauteng province are believed to be B.1.1.529, scientists said.

South Africa calls for urgent talks with WHO

South Africa has asked the World Health Organization (WHO) working group on virus evolution to hold an urgent meeting on Friday to discuss the new variant.

Researchers from the Network for Genomic Surveillance in South Africa said current PCR tests were able to detect the variant, which has also been found in Botswana and Hong Kong in people who traveled from South Africa.

South Africa was the first country to detect the beta variant last year, one of only four labeled "variants of concern" by the WHO over evidence those particular variants are more contagious and that vaccines are less effective against them.

Vaccine hesitancy in South Africa

South Africa has the highest pandemic numbers in Africa,  recording 2.95 million cases since the start of the pandemic, of which 89,657 have been fatal.

More than 25 million vaccines have been administered but only 35.2% of the adult population is fully vaccinated.

Earlier in the week, health authorities asked Johnson&Johnson to suspend delivery of the company's COVID-19 vaccine as it now has enough stock. 

Phaahla said the number of people getting vaccinated is dropping and that they are not reaching the target of 250,000 vaccinations a day.

lo/rs (AFP, Reuters, AP)