/ 18 November 2021

Covid-19 fourth wave likely to be less severe, but caution still advised

South African Minister Zweli Mkhize Visits Charlotte Maxeke Hospital Vaccination Ward
(Photo by Deaan Vivier/Beeld/Gallo Images via Getty Images)

With only 273 new Covid-19 infections reported on Tuesday, current evidence shows that the local government elections on 1 November did not affect the infection rate, a senior medical epidemiologist at the National Institute for Communicable Diseases, Harry Moutrie said at a briefing the NICD hosted on Wednesday.

Although no study was done to look at the influence of the elections on the current Covid-19 cases, the consistently low numbers are an indication that the elections did not result in a surge of infections, he said.

“To date, we have not seen any strong signals of any increase in cases that we would attribute to increased transmission to either the elections or perhaps more recently, religious festivals,” said Moutrie.

By Wednesday night, the numbers had increased to 566 new infections.

Moutrie was joined by other scientists from the South African Covid-19 Modeling Consortium (SACMC), who provided an update of what a fourth wave was likely to look like, based on several scenarios.

Based on a report that focused on projections of hospital admissions as the primary outcomes, deaths and infections are expected to be lower than previous waves, mainly because of increased vaccination coverage, particularly in the 60 years and above population.

The report said that even with continued behavioural fatigue, rapid vaccination of the adult population, which is expected to reach at least 70% by the end of March next year, provided a powerful tool to reduce severe illness and death. 

“The level of admissions was around 177 000 nationally in wave three and in wave three the 85% of excess deaths is around 93 000,” said Sheetal Silal, a mathematical modeller at the University of Cape Town.

“We can see in scenarios one, two, three and four that we do not get anywhere close to those levels. Our admissions are sitting somewhere around half of what was observed in wave three and with respect to death, around half of the deaths that were observed in waves two and three.

“Just because the peaks we are projecting are lower than we have seen in the previous waves, it does not mean that there may not be any breaches in capacity or capacity would run out in any of these provinces.” 

Silal added that hospital management should assess the projections and peak sizes concerning currently available capacity instead of the capacity available during the previous waves.

The projections suggest the vaccine’s ability to prevent severe illness did not wane.

“We have seen some studies that show that there is protection against severe illness for five months after vaccination. The most recently released study on the Pfizer vaccine showed that even after three months after the second dose of the vaccine, there was no evidence of the waning of effectiveness against severe illness,” she said.

The assumptions made in this report were made in the absence of local data and would be updated as it became available.

The scientists were unable to tell when the fourth wave might occur because the numbers of infections remained low, but they cautioning South Africans to continue observing the non-pharmaceutical measures.