As some parts of the globe still reel from the Delta variant of COVID-19, the emergence of the new Omicron variant has nations worried.
South Africa is being hit by a fourth wave of COVID-19 infections driven by the Omicron variant, which has been detected in seven of the country's nine provinces, Health Minister Joe Phaahla said on Friday.
South Africa, the country which first detected the new variant, saw its COVID-19 infections surge to a record three million on Friday as a new wave driven by the Omicron rips through parts of the country, as per official figures.
The government on Friday reported 16,055 new cases over a 24-hour period, taking the cumulative laboratory-confirmed cases to 3,004,203. In mid-November, South Africa was reporting about 300 cases a day.
"This increase represents a 24.3 percent positivity rate," the government-run National Institute for Communicable Diseases (NICD) said in a daily update.
COVID-19 surge in country
South Africa’s hospitals are so far coping with the surge, even those in Gauteng province, which accounts for more than 70 percent of all new infections, Health Minister Joe Phaahla said.
The majority of new cases reported on Friday, 72 percent, were detected in Gauteng province, the most populous of the country's provinces.
Gauteng which hosts the capital Pretoria and the country's economic and financial hub, Johannesburg, has emerged as the epicentre of the new variant since the new variant was first detected there last week.
The picture could change because most of those infected thus far have been younger people, who generally do not get as sick as older patients.
A leading epidemiologist Salim Abdool Karim had on Monday forecast that coronavirus cases in the continent's worst-hit country could see daily infections more than treble this week to more than 10,000.
Gauteng province surpassed the projection, recording 11,553 cases on Friday. Other provinces recorded less than 1,000 cases each.
The sharp rise in infections is blamed on the highly contagious new Omicron strain, which was first reported by South African scientists, on 25 November.
The numbers of fatalities, however, still remain relatively low, with 25 COVID-19 related deaths being reported on Friday, taking the death toll to 89,944 since the onset of the pandemic.
Reinfections three times more likely with Omicron, says research
But in a worrisome development, South African scientists reported that omicron appears more likely than earlier variants to cause reinfections among people who have already had a bout with COVID-19.
A preliminary study by South African scientists published earlier this week suggests the Omicron variant is three times more likely to cause reinfections compared to the Delta or Beta strains.
The findings, based on data collected by the country's health system, provide the first epidemiological evidence about Omicron's ability to evade immunity from prior infection.
The paper was uploaded on a medical preprint server and has not yet been peer-reviewed.
There were 35,670 suspected reinfections among 2.8 million individuals with positive tests until November 27. Cases were considered reinfections if they tested positive 90 days apart.
"Recent reinfections have occurred in individuals whose primary infections occurred across all three waves, with the most having their primary infection in the Delta wave," tweeted Juliet Pulliam, director of the South African DSI-NRF Centre of Excellence in Epidemiological Modelling and Analysis.
Pulliam cautioned that the authors did not have information about the individuals' vaccination status and therefore could not assess to what extent Omicron evades vaccine-induced immunity. The researchers plan to study this next.
"Data are also urgently needed on disease severity associated with Omicron infection, including in individuals with a history of prior infection," she said.
Michael Head, a scientist at the University of Southampton, praised the research as "high quality."
"This analysis does look very concerning, with immunity from previous infections being relatively easily bypassed. Might this all still be a ‘false alarm’? That is looking less and less likely," he said in a statement.
Study suggests past COVID-19 infection may not fend off Omicron
The country's scientists are also now warning that reinfections among people who’ve already battled COVID-19 appear to be more likely with the new Omicron variant than with earlier coronavirus mutants.
A research group has been tracking reinfections in South Africa and reported a jump with the arrival of omicron that they hadn't seen when two previous variants, including the extra-contagious delta variant, moved through the country.
The findings, posted online Thursday, are preliminary and haven't yet undergone scientific review. Nor did the researchers say what portion of the reinfections were confirmed as omicron cases — or whether they caused serious illness.
But the timing of the reinfection spike suggests that omicron “demonstrates substantial population-level evidence for evasion of immunity from prior infection," they wrote.
Exponential rise but vaccines work
Earlier, top South African scientist Anne von Gottberg, an expert at the National Institute for Communicable Diseases, forecast a surge in cases but said authorities expected vaccines would still be effective against severe outcomes.
"We believe the number of cases will increase exponentially in all provinces of the country," she said in a news conference with the World Health Organization's Africa region.
"We believe that vaccines will still however protect against severe disease," she added.
South Africa’s previous surge, driven by the delta variant in June and July, saw daily new cases reach a peak of more than 20,000. With a population of 60 million people, South Africa has recorded more than 2.9 million COVID-19 cases, including nearly 90,000 deaths.
It’s too early to be certain that the omicron variant is responsible for the rise in cases, but it is very possible, say experts. Standard PCR tests can suggest that a positive case is caused by Omicron, but only a full genetic sequencing can confirm it.
With inputs from agencies