The Covid-19 variant Omicron is inherently less severe with reduced hospitalisations even if a patient is unvaccinated, a study has found. People are 36 percent less likely to end up in hospital if they contract the Omicron variant compared to those with Delta.
The reduced risk was observed among both unvaccinated and vaccinated, although those who did have the vaccine had a far lower risk of severe symptoms. Researchers show this suggests Omicron is inherently less severe than previous strains of Covid-19.
In a study published in The Lancet Infectious Diseases, researchers studied all PCR confirmed cases in Denmark with samples taken from the date of the first Omicron-positive sample and the following month.
Among the 188,980 individuals with SARS-CoV-2 infection, a fifth had the omicron variant. Vaccination was associated with a 76 percent lower risk of hospitalisation, with cases slightly lower risk for Omicron compared to Delta.
Researchers were able to spot that individuals with Omicron were younger, had less pre-existing conditions, and were more often previously infected with SARS-CoV-2. Among hospitalised cases, a similar pattern was observed for Omicron compared with Delta with regards to age, comorbidity, and reinfection.
Hospitalised omicron cases were made up of more women (61 percent) than men (39 percent), whereas hospitalised delta cases were 51 percent men and 49 percent women.
Dr Peter Bager, at the Statens Serum Institut in Copenhagen, said: "We found a significantly lower risk of hospitalisation with omicron infection compared with delta infection among both vaccinated and unvaccinated individuals, suggesting an inherent reduced severity of Omicron. Our results could guide modelling of the effect of the ongoing global Omicron wave and thus health-care system preparedness.”
The research was presented at the European Congress of Clinical Microbiology and Infectious Diseases.
