South Africa is facing thousands of daily new infections and could be on the brink of its fifth coronavirus wave, Health Minister Joe Phaahla told reporters on Friday.

He noted that it would take some time before health authorities can fully assess the data over a seven-day period and declare that the wave has officially started. But the country has already surpassed the threshold of 6,237 new cases per day, according to the minister.

"So, whichever way we look at it, it does suggest that we may actually be entering the fifth wave much earlier" than previously expected, Phaahla said.

Health authorities in South Africa previously expected the next wave of infections to start in May or June, as the southern hemisphere moves from autumn to winter, according to a report by the Reuters news agency. The country had loosened restrictions amid falling cases last month.

No sign of new variants, but…

The current spike of infections caused an uptick in hospitalizations but there was no dramatic change in hospital admissions or deaths. Health Minister Phaala also said no new variants of the coronavirus have been reported in the African country.

"We've also been informed that when the new wave comes it will be driven by a new variant but at this stage, we have not been alerted to a definite new variant, except changes in the omicron," the minister was quoted as saying by South Africa's Eyewitness News.

At the same briefing, infectious disease expert Richard Lessells said omicron sub-lineages BA.4 and BA.5 were responsible for a rising share of infections, suggesting they may have a growth advantage compared to other omicron variations. At the same time, there was no sign that COVID caused by BA.4 and BA.5 was significantly more severe than before, said Waasila Jassat from the National Institute for Communicable Diseases.

Over one-half of South African adults still unvaccinated

The coronavirus omicron variant was first reported in South Africa in November last year, prompting many governments around the world to restrict travel to and from the country. Scientists eventually determined that omicron was highly infectious, but caused less severe symptoms among the infected.

Some observers have expressed concern that more coronavirus variants may surface, including those more infectious and more lethal than previously known. 

On Friday, South African Health Minister Phaala urged young people to get vaccinated, saying that over one-half of adults in Africa's most developed country haven't received a single COVID jab.

"We know that natural immunity wanes with time, and cannot be boosted," he said.

Edited by: Kieran Burke