Black adults were hospitalized at higher rates than whites during the U.S. Omicron wave.

According to a study published by the Centers for Disease Control and Prevention, black adults were hospitalized at a higher rate than white adults after Omicron became the main coronaviruses variant in the United States.

The rate of hospitalizations associated with the coronaviruses over that period was more than double that of the previous six months.

The hospitalization rate for non-Hispanic black adults was 3.8 times that of non-Hispanic white adults. It was the highest observed rate among all racial and ethnic groups.

The study was co-written by scientists from universities across the country and was led by Christopher A. Taylor, a member of the C.D.C.'s Covid-19 Emergency Response Team. The report was based on data from 99 counties in 14 states and was published in the Morbidity and Mortality Weekly Report.

When Omicron peaked in January, the rate of hospitalizations among the unvaccinated was four times that of people who had received a primary series of Covid vaccinations, and 12 times that of adults who had received additional doses or boosters.

Black Americans were less likely to get vaccine than white Americans. A wave of pro-vaccine campaigns and a surge of virus hospitalizations and deaths during the Delta wave that mostly involved the unvaccinated prompted many in the Black community to change their minds.

The gap was still there when Omicron hit. The percentage of black people in the United States who received a primary vaccine series by late January was 36.6%, and of those who received a booster, 43.9% did so. White people had percentages of 47.3 percent and 54.5%.

Poor access to health care and underlying medical conditions are some of the factors that could cause hospitalizations for Black adults, according to a study. It said that Omicron's heightened transmissibility may have amplified the risks for hospitalization. Black hospitalized patients received a primary vaccine series at a higher rate during the Omicron wave than during the Delta wave.

The findings suggest that the increased risk for hospitalization among Black adults during the Omicron-predominant period may be due to lower proportions of Black adults receiving both the primary vaccination series and booster doses.

Pam Belluck was involved in reporting.