Omicron cases have an approximately 15 to 20% reduced risk of hospitalisation compared to the previous Delta variant, researchers from Imperial College London said on Wednesday.
There was also a reduced risk of a longer hospitalisation stay, with Omicron cases 40-45% less likely to be hospitalised for one night or more.
The report looked at all PCR-confirmed Omicron cases in England in the first two weeks of December.
The estimates suggest that reinfection cases have a 50-60% reduced risk of a hospitalisation, the statement from Imperial College London said.
Yet the rapid spread of Omicron means that large numbers of infections could still lead to a high number of hospitalisations.
“Given the high transmissibility of the Omicron virus, there remains the potential for health services to face increasing demand if Omicron cases continue to grow at the rate that has been seen in recent weeks,” said Professor Neil Ferguson, director of Imperial’s MRC Centre for Global Infectious Disease Analysis.
A previous report from Imperial College London estimated that the risk of reinfection with the Omicron variant is 5.4 times greater than that of the Delta variant.
Figures from a Scottish pre-print study were also promising and suggested that Omicron is associated with a two-thirds reduction in the risk of hospitalisation compared to Delta.
The researchers said that booster doses offered substantial additional protection against symptomatic Omicron as well.
A separate study in South Africa, meanwhile, said that Omicron cases had a reduced risk of hospitalisation and of severe disease when compared to earlier Delta-infected individuals. But some of these results were attributed to high population immunity from previous waves of the virus.
