Study reveals that omicron has 80% less risk of hospitalization

South Africans who contract COVID-19 in the current fourth wave of infections are 80% less likely to be hospitalized if they contract the omicron variant, compared to other variants, according to a study published by the National Institute of Communicable Diseases.

Once hospitalized, the risk of serious illness does not differ from other variants, said the authors led by scientists Nicole Walter and Cheryl Cohen.

Compared with delta variant infections in South Africa between April and November, omicron infections are associated with a 70% lower risk of severe disease, they said. Data for the omicron variant was collected during the two months to November.

Since it was identified by South African scientists on November 25, the omicron variant has driven a record number of cases across the country. Africa’s most developed economy has fully inoculated about 44% of its adult population over a seven-month period.

Some limitations of the study

In data sent to a pre-printed medical journal, MedRxiv, the authors adjusted for several confounding factors that could influence the results, including age, sex, and whether the cases were known reinfections.

For severity of illness after admission, they also adjusted for the presence of other illnesses and prior immunization.

The study also showed that those infected with the omicron variant may have higher viral loads.

The study is “important,” although the use of so-called historical controls when compared to delta infections between April and November means its result may be time-biased, said Paul Hunter, a professor of medicine at the University of East Anglia, in the United Kingdom.

“So while omicron cases were less likely to end up in the hospital than delta cases, it is not possible to say if this is due to inherent differences in virulence or if this is due to increased immunity in the population in November. compared to earlier in the year, ”Hunter said.