Covid-19 pandemic at a ‘turning point’: groundbreaking study

More than half of children in SA have had Covid-19, as have about 80% of adults older than 50.

These data are according to a study by the Wits Vaccines and Infectious Diseases Analytics Research Unit led by Prof Shabir Madhi, published this week in the New England Journal of Medicine.

It indicates that the pandemic has reached a definite “turning point”, said Madhi.

It is the first peer-reviewed and published study of data to demonstrate decoupling between infections and severe Covid-19 disease and death.

The study, based on seroprevalence data in Gauteng, also found that at a subdistrict level, seropositivity was as high as 85% in the inner city, while seropositivity was 68% in unvaccinated individuals and 93% in vaccinated individuals.

By the time the Omicron variant reared its head, according to Madhi and the team, “South Africans had extensive community immunity because of high infection rates in the first three waves, as well as vaccinations”.

Despite many breakthrough infections and reinfections in the fourth wave, most were protected against severe disease and death.

The data also indicate that only 10% of those infected were confirmed as such, and the analyses of cases and death rates since the pandemic began indicate a clear and major “decoupling of incidence of infections relative to Covid-19 hospitalisation and death during the Omicron dominant wave in SA, compared with earlier waves”.

Notably, compared with the Delta variant-dominant third wave in SA — which contributed to 44% of Covid-19 hospitalisations and 50% of deaths since the start of the pandemic in Gauteng — the Omicron wave only contributed to 10% of hospitalisations and 3% of deaths.

In the 50-plus age group, only 2% of deaths since the start of the pandemic in Gauteng occurred during the course of the Omicron wave, whereas 53% occurred in the Delta variant-dominant wave before the vaccine rollout.

“The study findings indicate that we have reached a turning point in the Covid-19 pandemic, even in countries with a modest uptake of vaccines, but where there has been a high force of natural infection which has resulted in a huge loss of lives,” said Madhi.

He said that in SA, 490 people per 100,000 had died of Covid-19. 

This puts SA in the top 10 countries globally of Covid-19 fatality rates.

“When excess deaths are factored in, three times the official figure of 97,000 people in SA have died of Covid-19. The actual number of deaths from Covid-19 in SA is closer to 300,000 people,” he added.

The findings have significant implications for Africa, a continent where vaccines and resources to support vaccine rollout are limited and where hospitalisation for Covid-19 severely constrains public health facilities and resources.

He said the focus for vaccines should be on reaching 90% in high-risk groups rather than a lower percentage in the general population.