A lower share of people infected with the Omicron coronavirus variant are likely to require hospital treatment compared with cases of the Delta strain, according to healthcare data from South Africa, Denmark, and the UK.

The findings by separate research teams raise hopes that there will be fewer cases of severe disease than those caused by other strains of the virus, but the researchers cautioned that Omicron’s high degree of infectiousness could still strain health services.

The reduction in severe illness was likely to stem from Omicron’s greater propensity, compared with other variants, to infect people who have been vaccinated or previously infected, experts stressed, though the UK studies also hinted at a possible drop in intrinsic severity.