Residual Disparities in US Children Hospitalized Due to All-Cause Pneumonia Following Implementation of Childhood PCV13 in National Immunization Program.

Background/Objectives: Pneumonia is a leading cause of hospitalization among children in the United States, with a disproportionate burden in certain racial, socioeconomic, and clinical subgroups. The 13-valent pneumococcal conjugate vaccine (PCV13), introduced in 2010, significantly reduced pneumococcal disease overall, but its effect on disparities in all-cause hospitalized pneumonia (AC-hPNA) remains unclear. This study evaluated changes in AC-hPNA rates by age, race, comorbidity profile, and household income (HHI) before and after PCV13 implementation. Methods: A retrospective cohort study using Optum's de-identified Clinformatics® DataMart (2007-2019) included children < 18 years. Rates (per 100,000 person-years) and incidence rate ratios were calculated for four periods: pre-PCV13 (2008-2009), peri-PCV13 (2010-2012), post-PCV13#1 (2013-2016), and post-PCV13#2 (2017-2019). Analyses were stratified by age group and, within each, by race, comorbidity profile (low, at-risk), and HHI. Results: Among 10.1 million children, AC-hPNA rates declined by 51-57% from pre-PCV13 to post-PCV13#2 across all age groups, with the largest reductions in children aged <2 years. Declines occurred across all race, comorbidity, and HHI subgroups; however, rates remained several-fold higher among at-risk children. Persistent disparities were observed among Black children < 2 years, children aged 2-5 years with HHI < $50,000, and children aged 6-17 years with HHI of $50,000-$99,999. Conclusions: Substantial reductions in rates of pediatric AC-hPNA were observed in the period subsequent to the introduction of routine PCV13, yet residual disparities persist among children with comorbidities and select racial and income groups. Targeted strategies are needed to address these gaps.