South Africa will likely be hit by a fourth wave of infections but its impact probably won’t be as severe as during earlier surges, new modelling prepared for the government shows.

Sero-prevalence surveys and other data indicate that an estimated 60-70% of the population has already contracted Covid-19, which together with vaccinations will provide protection from severe disease, the South African Covid-19 Modelling Consortium said in a online presentation on Wednesday. Even its worst-case scenario projected that deaths and hospitalisations during a fourth wave would be substantially lower than during prior surges.

While South Africa’s current caseload is “incredibly low”, it’s “very hard to commit to say South Africa is over the worst” of the coronavirus, said Harry Moultrie, a senior epidemiologist at the National Institute for Communicable Diseases, which coordinated the modelling.

“It’s going to be a bumpy ride,” he said. “We don’t know where this virus is going to take us. We will still be seeing hospital admissions and deaths related to Covid for years to come.”

The seven-day rolling average of new infections in South Africa has dropped to below 300, from a third-wave peak of almost 20 000 in July.

The country has had 2.93 million confirmed coronavirus cases and 89 504 of those who’ve been diagnosed with the disease have died from it, although excess death numbers indicate the true toll may be much higher. About 34% of the nation’s 39.8 million adults have been fully vaccinated.

While some northern hemisphere countries are seeing severe fourth waves of infection driven by the spread of the Delta variant, that’s not a good indicator South Africa will follow a similar path because the strain has already spread widely in the country, according to Gesine Meyer-Rath, a member of the modelling consortium.

“We have paid in a way with high deaths and a lot of destruction” during previous waves, Meyer-Rath said. “We don”t think we will have a super-fast case increase again” unless a highly transmissible new variant emerges, she said. — (c) 2021 Bloomberg LP