{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,22]],"date-time":"2026-07-22T23:05:05Z","timestamp":1784761505325,"version":"3.55.0"},"reference-count":20,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,1,31]],"date-time":"2026-01-31T00:00:00Z","timestamp":1769817600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Beijing Hospitals Authority Ascent Plan","award":["DFL20221103"],"award-info":[{"award-number":["DFL20221103"]}]},{"name":"High-level Public Health Talents Training Plan","award":["AL-02-19"],"award-info":[{"award-number":["AL-02-19"]}]},{"name":"American Chinese Medical Foundation","award":["21-433"],"award-info":[{"award-number":["21-433"]}]},{"name":"Research Foundation of Capital Institute of Pediatrics","award":["LCYJ-2025-02 to Yu Tian"],"award-info":[{"award-number":["LCYJ-2025-02 to Yu Tian"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Background: 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. Methods: 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\u2013Wallis and chi-square (\u03c72)\/Fisher\u2019s exact tests with Bonferroni correction. Results: Timely vaccination was lower than the national healthy child benchmarks for all NIP vaccines (all p &lt; 0.001); the Japanese encephalitis virus (JE; 24.0%) and measles-containing vaccine (MCV; 25.9%) had the lowest timely completion. A subset of CSHCNs did not receive recommended catch-up vaccinations, primarily due to persistent caregivers\u2019 concern and point of vaccination (POV) staff\u2019s hesitancy. Delays clustered in neonatal\/perinatal disorders for Bacillus Calmette\u2013Gu\u00e9rin (BCG) and hepatitis B vaccine, dose 1 (HepB1). Catch-up completion was highest for hepatitis B vaccine, dose 3 (HepB3) (86.3%) and BCG (81.8%), and lowest for the diphtheria and tetanus vaccine (DT) (49.4%); MCV2 completion was particularly low in hematological diseases. Immunoglobulin A (IgA) and immunoglobulin G (IgG) concentrations were significantly lower in neonatal\/perinatal disorders and infectious disease groups versus neurological and immune disorder groups (p &lt; 0.05). No severe adverse events were reported after catch-up. Conclusions: CSHCNs in China face substantial barriers to timely NIP immunization. Timeliness and catch-up vary substantially by vaccine and underlying condition; neonatal\/perinatal disorders contribute disproportionately to early-life delays. Disease-specific guidance, strengthened POV\u2013specialist clinic coordination, immunological monitoring, and supportive policies could improve the vaccination coverage and effectiveness in this vulnerable population.<\/jats:p>","DOI":"10.3390\/vaccines14020149","type":"journal-article","created":{"date-parts":[[2026,2,2]],"date-time":"2026-02-02T09:48:08Z","timestamp":1770025688000},"page":"149","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Timeliness of Routine Vaccination, Catch-Up Completion, and Immune Function in Chinese Children with Special Healthcare Needs: A Retrospective Cohort Study"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-7254-243X","authenticated-orcid":false,"given":"Yuyuan","family":"Zeng","sequence":"first","affiliation":[{"name":"Capital Institute of Pediatrics, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100020, China"},{"name":"Department of Child Health Care, Capital Institute of Pediatrics, Capital Center for Children\u2019s Health, Capital Medical University, Beijing 100020, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xihan","family":"Li","sequence":"additional","affiliation":[{"name":"School of Public Health, Capital Medical University, Beijing 100069, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yu","family":"Tian","sequence":"additional","affiliation":[{"name":"Department of Child Health Care, Capital Institute of Pediatrics, Capital Center for Children\u2019s Health, Capital Medical University, Beijing 100020, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yuming","family":"Liu","sequence":"additional","affiliation":[{"name":"Department of Global Health, School of Public Health, Peking University, Beijing 100191, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jianhong","family":"Wang","sequence":"additional","affiliation":[{"name":"Department of Child Health Care, Capital Institute of Pediatrics, Capital Center for Children\u2019s Health, Capital Medical University, Beijing 100020, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qi","family":"An","sequence":"additional","affiliation":[{"name":"Department of Child Health Care, Capital Institute of Pediatrics, Capital Center for Children\u2019s Health, Capital Medical University, Beijing 100020, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chuanyu","family":"Yang","sequence":"additional","affiliation":[{"name":"Capital Institute of Pediatrics, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100020, China"},{"name":"Department of Child Health Care, Capital Institute of Pediatrics, Capital Center for Children\u2019s Health, Capital Medical University, Beijing 100020, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bo","family":"Zhou","sequence":"additional","affiliation":[{"name":"Department of Child Health Care, Capital Institute of Pediatrics, Capital Center for Children\u2019s Health, Capital Medical University, Beijing 100020, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lili","family":"Zhang","sequence":"additional","affiliation":[{"name":"Department of Child Health Care, Capital Institute of Pediatrics, Capital Center for Children\u2019s Health, Capital Medical University, Beijing 100020, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3660-1276","authenticated-orcid":false,"given":"Yangmu","family":"Huang","sequence":"additional","affiliation":[{"name":"Department of Global Health, School of Public Health, Peking University, Beijing 100191, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5536-781X","authenticated-orcid":false,"given":"Lin","family":"Wang","sequence":"additional","affiliation":[{"name":"Department of Child Health Care, Capital Institute of Pediatrics, Capital Center for Children\u2019s Health, Capital Medical University, Beijing 100020, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,31]]},"reference":[{"key":"ref_1","unstructured":"National Health Commission of the People\u2032s Republic of China (2021). 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Immunother."}],"container-title":["Vaccines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-393X\/14\/2\/149\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,10]],"date-time":"2026-02-10T05:14:11Z","timestamp":1770700451000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-393X\/14\/2\/149"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,1,31]]},"references-count":20,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2026,2]]}},"alternative-id":["vaccines14020149"],"URL":"https:\/\/doi.org\/10.3390\/vaccines14020149","relation":{},"ISSN":["2076-393X"],"issn-type":[{"value":"2076-393X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,1,31]]}}}