Patients hospitalized with Omicron BA.5 are more likely to die than those with other COVID-19 variants or with flu, according to a new study led by the US Centers for Disease Control and Prevention (CDC).

The study, published in the Open Forum Infectious Diseases, looked at the proportion of hospitalized Covid-19 and influenza patients admitted to a US intensive care unit (ICU) in 2021 and 2022.

The findings showed that the percentage of hospitalized Covid-19 patients admitted to the ICU was similar to seasonal influenza but hospitalized Covid-19 patients during the Omicron BA.5 period continued to experience more in-hospital deaths than adults hospitalized with influenza.

The association with increased in-hospital death was strongest among adults aged 18-49 years; there was no significant difference in deaths between patients with COVID-19 and influenza among older ages.

“The epidemiology of Covid-19 continues to evolve. Our data suggest that from the Delta-predominant period to the Omicron BA.5-predominant period, the severity of patients hospitalized with Covid-19 generally decreased,” said Noah Kojima, from the CDC’s Influenza Division in Georgia.

The study included 5,777 and 2,363 eligible adults hospitalized for COVID-19 and flu, respectively.

Amid the Delta variant-predominant period (October to December 2021), 1,632 were hospitalized, compared with 1,451 during the Omicron BA.5 period (June to September 2022).

During the 2011-22 respiratory virus season, 2,363 people were hospitalized for flu.

Although there was a decline in the severity of Covid-19 hospitalization during the study period, overall severity during later Omicron sublineage periods (BA.2 and BA.5) was generally similar.

READ
More Screen Time May Lower Language Development Skills in Toddlers: Study

Continued monitoring of severity trends is warranted as new variants circulate and population-level immunity changes, the team said.

The reduced disease severity amid Omicron BA.5 predominance is likely multifactorial, including increased population-level SARS-CoV-2 immunity from vaccination and previous infection, broader availability of effective drugs, and refined clinical management strategies, they noted.