Adolescent Immunization Rates in a Medicaid Managed Care Population During the COVID-19 Pandemic: Louisiana, 2019-2023.

Objectives. To assess changes in adolescent immunization rates among enrollees in a Louisiana Medicaid managed care organization from 2019 through 2023 and examine sociodemographic differences. Methods. Using Louisiana's immunization information system and Healthcare Effectiveness Data and Information Set (HEDIS) specifications, we calculated human papillomavirus, meningococcal, tetanus-diphtheria-acellular pertussis, and combined-series immunization rates and compared demographic trends from 2020 to 2023. Results. Combined-series rates decreased from 45.6% in 2020 to 38.0% in 2022, then partially recovered to 42.6% in 2023. Trends were broadly similar by race and sex. Rural adolescents had consistently lower rates and a larger decrease, from 38.4% to 28.8%, followed by recovery to 37.2%. Spanish-speaking families maintained substantially higher rates and experienced a smaller decrease, from 66.9% in 2020 to 61.9% in 2022. Conclusions. Adolescent immunization rates decreased during the COVID-19 pandemic and had not fully recovered by 2023, with persistent rural disparities. Public Health Implications. Recovery efforts should prioritize rural Medicaid populations and identify practices associated with sustained coverage among Spanish-speaking families. (Am J Public Health. Published online ahead of print September 24, 2026:e1-e8. https://doi.org/10.2105/AJPH.2026.308717).