Coronavirus: Omicron less severe even for unvaccinated, South Africa study finds
- It shows 8 per cent were hospitalised or died within 14 days of being diagnosed with Covid-19 in the Omicron-driven wave compared with 16.5 per cent over the three earlier waves
- South Africa, the first country to have a major outbreak caused by the strain, has so far shown lower hospitalisation and death rates
The Omicron coronavirus variant causes less severe disease than the Delta strain even in those who are unvaccinated or who haven’t had a prior Covid-19 infection, a study from South Africa’s Western Cape province showed.
The research in the region where Cape Town is the capital compared 11,609 patients from the first three waves of infection, the most recent of which was caused by the Delta variant, and 5,144 patients from the latest Omicron-driven wave.
The findings add to growing evidence that while more infectious, Omicron may be less virulent than some of its predecessors. Data from South Africa, the first country to have a major outbreak caused by the strain, has so far shown lower hospitalisation and death rates.
Still, with over a quarter of the population vaccinated and a prior infection rate of 70 per cent to 80 per cent, there has been concern that that may be masking the danger presented by the variant.
“Ours is the first study from a setting of high prior seroprevalence to demonstrate less severe disease in wave four after adjusting for both vaccination and prior diagnosed infection,” the researchers said in the study.
“Even after this protection was considered there was a likely reduction of the most severe outcomes in wave four,” indicating possible reduction in virulence of Omicron, they said.