P-2002. Incidence and Risk of COVID-19 Hospitalization Among Unvaccinated Children

Abstract Background Although most children often experience mild illness following SARS-CoV-2 infection, some can develop severe disease requiring hospitalization, admission into an intensive care unit (ICU), or die. Methods Children aged 0 - < 18 years, members of Kaiser Permanente Northern California (KPNC), an integrated healthcare organization with more than 4 more million members, were followed from March 1, 2020, until the earliest occurrence of: chart-confirmed COVID-19 hospitalization, disenrollment from KPNC, age 18 years, receipt of COVID-19 vaccine, death, or study end (December 31, 2022). We calculated the incidence rate of hospitalization by SARS-CoV-2 variant period and by age group. We determined risk factors for hospitalization using Poisson regression. We also conducted descriptive analyses of hospitalized cases. Results Among 1,107,799 children, 423 were hospitalized for COVID-19 during follow-up. The incidence of hospitalization increased with each new SARS-CoV-2 variant and was highest among children aged < 6 months. Among the < 6-month-olds, the incidence rate per 100,000 person-months was 7 during pre-delta, 13.3 during delta and 22.4 during omicron. Black (RR= 2.05, 95% CI: 1.33 – 3.16) and Hispanic children (RR = 1.82, 95% CI: 1.34 – 2.46) and children with any comorbidities were at high risk of hospitalization (RR = 3.81, 95% CI: 2.94 – 4.95). Overall, 20.3% of hospitalized children were admitted to an intensive care unit (ICU), but ICU admission was 36.1% among 12 - < 18-year-olds. The majority of ICU admits (91.8%) had no comorbidities. Conclusion Children too young to be vaccinated had the highest incidence of COVID-19 hospitalization, while adolescents had the highest proportion of ICU admissions. To prevent severe disease in children and adolescents, everyone eligible should be vaccinated. Disclosures Nicola P. Klein, MD, PhD, CSL Seqirus: Grant/Research Support|GlaxoSmithKline: Grant/Research Support|Merck: Grant/Research Support|Pfizer: Grant/Research Support|Sanofi Pasteur: Grant/Research Support