Incidence of Invasive Pneumococcal Disease in US Children by Risk Group, 1998-2023.

BACKGROUND

Children with risk conditions are vulnerable to invasive pneumococcal disease (IPD) and are targeted for routine and supplemental pneumococcal vaccination. This study aimed to quantify the incidence of IPD in US children by risk group since pneumococcal conjugate vaccine introduction.

METHODS

Invasive pneumococcal disease episodes were identified in the Merative™ MarketScan® Commercial Database (1998-2023) and Multi-State Medicaid Database (2001-2023) using inpatient and outpatient claims. Annual IPD incidence rates (IRs) were calculated as episodes per 100 000 person-years (PY) for children <18 years of age, overall and by insurance type, age, and risk group. Incidence rate ratios (IRRs) were calculated to compare IR for children with chronic medical conditions (CMC) and immunocompromising conditions (IC) with those with no CMC/IC.

RESULTS

A total of 3538 commercially-insured and 3268 Medicaid-insured children with ≥1 IPD episode were identified among 128.9 million (121.9 million PYs) and 71.2 million eligible children (65.4 million PYs), respectively. Across age and risk groups, IPD IRs decreased over time, regardless of insurance type. Commercially-insured children with CMC and IC had 3.1-8.6 and 19.1-74.5 times higher IPD IRs, respectively, than those without CMC/IC, with similar patterns in the Medicaid database. Invasive pneumococcal disease IRs were the highest among children <2 years, while risk-group disparities were greater among older children. Incidence rate ratios comparing CMC and IC vs. no CMC/IC increased over time, indicating widening disparities.

CONCLUSIONS

Invasive pneumococcal disease IRs among children with CMC/IC remain substantially higher than those without CMC/IC, and IRRs for children with risk conditions have increased over time. The risk-group disparities were more pronounced in older children. Better prevention strategies are needed to prevent IPD in children with risk conditions.