biostudies-literatureZeng YBeijing Hospitals Authority Ascent PlanResearch Foundation of Capital Institute of PediatricsAmerican Chinese Medical FoundationHigh-level Public Health Talents Training Plan149https://www.ebi.ac.uk/biostudies/studies/S-EPMC12945083biostudies-literatureUnknown14(2)<h4>Background</h4>Children with special healthcare needs (CSHCNs) face persistent barriers to timely immunization in China, but comparative evidence across disease groups and vaccines, and data on immune function, are limited.<h4>Methods</h4>We conducted a retrospective cohort study linking electronic medical records, vaccination records, and a structured telephone and questionnaire follow-up. We estimated timely vaccination by National Immunization Program (NIP) dose definitions, assessed catch-up completion at follow-up, and compared cellular/humoral/complement immune indices with published pediatric reference ranges. Group differences used ANOVA/Kruskal-Wallis and chi-square (χ²)/Fisher's exact tests with Bonferroni correction.<h4>Results</h4>Timely vaccination was lower thaVaccinesTimeliness of Routine Vaccination, Catch-Up Completion, and Immune Function in Chinese Children with Special Healthcare Needs: A Retrospective Cohort Study.PMC12945083LCYJ-2025-02 to Yu TianAL-02-1921-433DFL20221103Li XLiu YAn QHuang YTian YZhou BZeng YZhang LWang JYang CWang LfalseTimeliness of Routine Vaccination, Catch-Up Completion, and Immune Function in Chinese Children with Special Healthcare Needs: A Retrospective Cohort Study.<h4>Background</h4>Children with special healthcare needs (CSHCNs) face persistent barriers to timely immunization in China, but comparative evidence across disease groups and vaccines, and data on immune function, are limited.<h4>Methods</h4>We conducted a retrospective cohort study linking electronic medical records, vaccination records, and a structured telephone and questionnaire follow-up. We estimated timely vaccination by National Immunization Program (NIP) dose definitions, assessed catch-up completion at follow-up, and compared cellular/humoral/complement immune indices with published pediatric reference ranges. Group differences used ANOVA/Kruskal-Wallis and chi-square (χ²)/Fisher's exact tests with Bonferroni correction.<h4>Results</h4>Timely vaccination was lower tha2026-01-01T00:00:00Z2026 Jan2026-07-11T03:14:38.053Z2026-07-11T03:11:47.929ZS-EPMC129450834174607010.3390/vaccines14020149