A U.S. study released Tuesday shows that during the surge of the COVID-19 omicron variant, hospitalization rates of unvaccinated children ages 5-11 were twice those of children who had received shots.
The study by the U.S. Centers for Disease Control and Prevention looked at nearly 400 cases in 14 states between mid-December and late February.
Among the 397 children who were hospitalized with COVID-19 during the omicron wave, 87% were unvaccinated, the study found.
The average length of hospital stay for unvaccinated children was three days, compared with two days for vaccinated children with COVID-19.
The vaccinated children who were hospitalized did not require high degrees of breathing support such as nasal oxygen tubes or mechanical ventilation, according to the CDC.
The omicron variant set records for coronavirus infections in the United States in January, causing more infections than the original SARS-CoV-2 strain of the virus and an increase in hospitalizations among those younger than 18.
The Pfizer COVID-19 vaccine had been authorized by U.S regulators for children ages 5-11 before the omicron surge in October.
During the omicron surge, unvaccinated children in the age group had a hospitalization rate 2.1 times higher than vaccinated children, according to the study.
According to CDC data, only 28% of children between 5-11 are fully vaccinated, amounting to about 8 million nationwide.
The study also found that hospitalization rates among children in the age group were higher during the omicron wave than during the delta wave.