Hospitalization rates were high during the omicron BA.2-predominant COVID-19 period and were highest among unvaccinated adults, according to research published in Morbidity and Mortality Weekly Report. H. Keipp Talbot, MD, and colleagues used data from the COVID-19-Associated Hospitalization Surveillance Network to describe recent COVID-19- associated hospitalization rates among adults during the period coinciding with omicron BA.2
predominance (March 20 to May 31, 2022). Weekly hospitalization rates increased threefold among adults aged 65 and older, from 6.9 per 100,000 population in the week ending April 2, 2022 to 27.6 for the week ending May 28, 2022. During the same interval, hospitalization rates increased 1.7-fold for adults aged 18-64. Hospitalization rates were 3.4 times higher for unvaccinated versus vaccinated adults. Among hospitalized non-pregnant patients in this period, 39.1% had received a primary vaccination series and one booster or additional dose, and 5.0% had received a primary series and two or more boosters or additional doses.