Early data suggests South Africa’s Covid hospitalizations are lower in the Omicron wave, but caveats apply.

Five weeks of data from the administrative capital Pretoria and the surrounding municipality show that hospitalizations are lower across all age groups. Among those aged 60 years and older, rates of severe illness appear to be 50 percent lower, compared with the Delta wave. This age group is also the most vaccinated across South Africa, in both rural and urban areas.

“For the first time, there are more nonsevere than severe patients in hospital,” said Dr. Jassat, who leads the hospital admissions surveillance at the institute.

“We have to interpret the less severity data in light of the high seroprevalence and some vaccination coverage,” Dr. Jassat said.

As this latest outbreak spreads to other parts of South Africa, that picture may change, she warned.

Hospital admissions are rising rapidly in KwaZulu-Natal, where the percentage of adults with at least one dose of a vaccine is the lowest in the country, at less than 38 percent. The province has seen its daily hospital admissions climb to 971 on Dec. 15 from 79 on Dec. 1. The number of intensive care unit admissions has also increased, rising to 22.

Most of these patients are unvaccinated, said Dr. Sandile Tshabalala, the head of the province’s health department, and 41 percent of critical care patients need ventilation.

Early data on the spread of Omicron in South Africa seems to echo research suggesting that vaccination will reduce the risk of severe disease. In the Western Cape, where two thirds of those over age 60 are vaccinated, the gap between new infections and admissions has increased between waves as vaccination rates increased, said the head of the province’s department of health, Dr. Keith Cloete.

And in Gauteng Province, the test positivity rate seems to be decreasing, dipping to 25 percent after hovering around 30 percent in the last week and raising hopes that the wave may be cresting. That rate, however, is increasing in all other provinces, as new cases climb nationally.