Lower risk of hospitalisation with Omicron versus Delta, days study

A South African study suggests reduced risks of hospitalisation and severe disease in people infected with the Omicron coronavirus variant versus the Delta one, though the authors say some of that is likely due to high population immunity. Questions about Omicron's virulence are at the heart of scientific and political debate in many countries, as governments grapple with how to respond to the spread of the variant while researchers race to understand it.

The new study, which has not been peer-reviewed, sought to assess the severity of disease by comparing data about Omicron infections in October and November with data about Delta infections between April and November, all in South Africa. The analysis was carried out by a group of scientists from the National Institute for Communicable Diseases (NICD) and major universities.

The authors found the risk of hospital admission was roughly 80% lower for those infected with Omicron compared with Delta. However, they included several caveats and cautioned against jumping to conclusions about the intrinsic characteristics of Omicron.