{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T08:38:50Z","timestamp":1785400730097,"version":"3.56.0"},"reference-count":31,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T00:00:00Z","timestamp":1784505600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Young Medical Talents Training Program of Shanghai Pudong New Area Health Commission","award":["PWRq2023-24"],"award-info":[{"award-number":["PWRq2023-24"]}]},{"award":["PWRq2023-24"],"award-info":[{"award-number":["PWRq2023-24"]}],"id":[{"id":"https:\/\/ror.org\/041s47w50","id-type":"ROR","asserted-by":"publisher"}]},{"name":"Shanghai Three-year Action Plan to Strengthen the Construction of Public Health System Excellent Academic Leader Project","award":["GWVI-11.2-XD08"],"award-info":[{"award-number":["GWVI-11.2-XD08"]}]},{"name":"Shanghai Pudong New Area Science and Technology Development Fund Project","award":["PKJ2023-Y34"],"award-info":[{"award-number":["PKJ2023-Y34"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Background: Children with congenital heart disease (CHD) are highly vulnerable to influenza, yet real-world vaccine effectiveness (VE) data in this post-operative population are lacking, especially in China. This study estimated influenza VE against medically attended influenza-like illness (ILI) in post-operative children with CHD using inverse probability of treatment weighting (IPTW) to address confounding. Methods: We retrospectively enrolled 194 children who underwent CHD surgery in Shanghai (January\u2013July 2023). Vaccination records were obtained from the Shanghai Immunization Information System, and ILI episodes were captured via structured interviews. The primary analysis used doubly robust quasi-Poisson regression on an IPTW pseudo-population. VE = (1 \u2212 RR) \u00d7 100%. Sensitivity analyses included multivariable Poisson regression, marginal structural models, and stabilized IPTW. Results: Vaccination coverage was 21.6% (42\/194). After IPTW, all covariates were well-balanced (SMD &lt; 0.10). The primary VE was 50.9% (95% CI: 11.0\u201372.9%). Sensitivity estimates ranged from 49.6% to 56.6%. Subgroup analyses showed consistently protective point estimates. Conclusions: Influenza vaccination provided moderate, robust protection (\u224851% VE) against ILI in post-operative CHD children, comparable to healthy pediatric populations. Our results reinforce the urgent need to prioritize influenza immunization in this vulnerable group and offer critical baseline data for China.<\/jats:p>","DOI":"10.3390\/vaccines14070631","type":"journal-article","created":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T07:54:13Z","timestamp":1784534053000},"page":"631","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Influenza Vaccine Effectiveness Against Influenza-like Illness in Post-Operative Children with Congenital Heart Disease: A Retrospective Cohort Study Using Inverse Probability of Treatment Weighting"],"prefix":"10.3390","volume":"14","author":[{"given":"Rui","family":"Liu","sequence":"first","affiliation":[{"name":"School of Public Health, Dali University, 2 Hongsheng Road, Dali 671003, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pengfei","family":"Deng","sequence":"additional","affiliation":[{"name":"Shanghai Pudong New Area Center for Disease Control and Prevention (Shanghai Pudong New Area Health Supervision Institute), 3039 Zhangyang Road, Pudong New Area, Shanghai 200136, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tian","family":"Yang","sequence":"additional","affiliation":[{"name":"Shanghai Pudong New Area Center for Disease Control and Prevention (Shanghai Pudong New Area Health Supervision Institute), 3039 Zhangyang Road, Pudong New Area, Shanghai 200136, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yun","family":"Pan","sequence":"additional","affiliation":[{"name":"Department of Pediatric Cardiology, Shanghai Children\u2019s Medical Center, Shanghai Jiao Tong University School of Medicine, 1678 Dongfang Road, Pudong New Area, Shanghai 200127, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhuoming","family":"Xu","sequence":"additional","affiliation":[{"name":"Department of Pediatric Cardiology, Shanghai Children\u2019s Medical Center, Shanghai Jiao Tong University School of Medicine, 1678 Dongfang Road, Pudong New Area, Shanghai 200127, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Laibao","family":"Yang","sequence":"additional","affiliation":[{"name":"Shanghai Pudong New Area Center for Disease Control and Prevention (Shanghai Pudong New Area Health Supervision Institute), 3039 Zhangyang Road, Pudong New Area, Shanghai 200136, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Caoyi","family":"Xue","sequence":"additional","affiliation":[{"name":"Pudong Institute for Health Development, 818 Laiyang Road, Pudong New Area, Shanghai 200129, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qizhang","family":"Wang","sequence":"additional","affiliation":[{"name":"Shanghai Pudong New Area Center for Disease Control and Prevention (Shanghai Pudong New Area Health Supervision Institute), 3039 Zhangyang Road, Pudong New Area, Shanghai 200136, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,20]]},"reference":[{"key":"ref_1","unstructured":"World Health Organization (2022). Vaccines against influenza: WHO position paper\u2014May 2022. Wkly. Epidemiol. Rec., 97, 185\u2013208."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1285","DOI":"10.1016\/S0140-6736(17)33293-2","article-title":"Estimates of global seasonal influenza-associated respiratory mortality: A modelling study","volume":"391","author":"Iuliano","year":"2018","journal-title":"Lancet"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"53","DOI":"10.1016\/j.jpeds.2018.08.040","article-title":"Prevalence of congenital heart disease at live birth in China","volume":"204","author":"Zhao","year":"2019","journal-title":"J. Pediatr."},{"key":"ref_4","first-page":"1736","article-title":"Congenital heart defects and concurrent diagnoses in influenza hospitalization in the Pediatric Health Information System study, 2004\u20132019","volume":"45","author":"Stephens","year":"2024","journal-title":"Pediatr. Cardiol."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Ghimire, L.V., Chou, F.S., and Moon-Grady, A.J. (2020). Impact of congenital heart disease on outcomes among pediatric patients hospitalized for influenza infection. BMC Pediatr., 20.","DOI":"10.1186\/s12887-020-02344-x"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"e13418","DOI":"10.1111\/sji.13418","article-title":"Long-term immunological changes after corrective cardiac surgery","volume":"100","author":"Amirov","year":"2024","journal-title":"Scand. J. Immunol."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2319967","DOI":"10.1080\/21645515.2024.2319967","article-title":"Using big data to analyze the vaccination status of children with congenital heart disease in Yinzhou District, China","volume":"20","author":"Zhang","year":"2024","journal-title":"Hum. Vaccines Immunother."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Esposito, S., Aurelio, C., Cifaldi, M., Lazzara, A., Viafora, F., and Principi, N. (2026). Prevention of respiratory infections in children with congenital heart disease: Current evidence and clinical strategies. Vaccines, 14.","DOI":"10.3390\/vaccines14010011"},{"key":"ref_9","unstructured":"Chinese National Influenza Surveillance Network (2026, July 15). Influenza Surveillance Weekly Report, Week 35, 2025. Available online: https:\/\/www.chinacdc.cn\/jksj\/jksj04_14249\/."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"3083","DOI":"10.1002\/sim.3697","article-title":"Balance diagnostics for comparing the distribution of baseline covariates between treatment groups in propensity-score matched samples","volume":"28","author":"Austin","year":"2009","journal-title":"Stat. Med."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"3661","DOI":"10.1002\/sim.6607","article-title":"Moving towards best practice when using inverse probability of treatment weighting (IPTW) using the propensity score to estimate causal treatment effects in observational studies","volume":"34","author":"Austin","year":"2015","journal-title":"Stat. Med."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"383","DOI":"10.1097\/EDE.0b013e3181d61eeb","article-title":"Negative controls: A tool for detecting confounding and bias in observational studies","volume":"21","author":"Lipsitch","year":"2010","journal-title":"Epidemiology"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"656","DOI":"10.1093\/aje\/kwn164","article-title":"Constructing inverse probability weights for marginal structural models","volume":"168","author":"Cole","year":"2008","journal-title":"Am. J. Epidemiol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"550","DOI":"10.1097\/00001648-200009000-00011","article-title":"Marginal structural models and causal inference in epidemiology","volume":"11","author":"Robins","year":"2000","journal-title":"Epidemiology"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1149","DOI":"10.1093\/aje\/kwj149","article-title":"Variable selection for propensity score models","volume":"163","author":"Brookhart","year":"2006","journal-title":"Am. J. Epidemiol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"211","DOI":"10.1007\/s10654-019-00494-6","article-title":"Principles of confounder selection","volume":"34","author":"VanderWeele","year":"2019","journal-title":"Eur. J. Epidemiol."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Lee, B.K., Lessler, J., and Stuart, E.A. (2011). Weight trimming and propensity score weighting. PLoS ONE, 6.","DOI":"10.1371\/journal.pone.0018174"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"962","DOI":"10.1111\/j.1541-0420.2005.00377.x","article-title":"Doubly robust estimation in missing data and causal inference models","volume":"61","author":"Bang","year":"2005","journal-title":"Biometrics"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"761","DOI":"10.1093\/aje\/kwq439","article-title":"Doubly robust estimation of causal effects","volume":"173","author":"Funk","year":"2011","journal-title":"Am. J. Epidemiol."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"273","DOI":"10.1111\/j.1524-4733.2009.00671.x","article-title":"Use of stabilized inverse propensity scores as weights to directly estimate relative risk and its confidence intervals","volume":"13","author":"Xu","year":"2010","journal-title":"Value Health"},{"key":"ref_21","unstructured":"World Health Organization (2026, July 15). Global Influenza Strategy 2019\u20132030. Available online: https:\/\/www.who.int\/publications\/i\/item\/9789241515320."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2412887","DOI":"10.1080\/21645515.2024.2412887","article-title":"Epidemiological analysis of influenza vaccination coverage in Pudong New Area, Shanghai (2013\u20132023): Implications for influenza vaccination strategies","volume":"20","author":"Deng","year":"2024","journal-title":"Hum. Vaccin. Immunother."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2592428","DOI":"10.1080\/21645515.2025.2592428","article-title":"Vaccination status in children with congenital heart disease in Wuxi, China: Analysis of retrospective data","volume":"21","author":"Wang","year":"2025","journal-title":"Hum. Vaccin. Immunother."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"337","DOI":"10.1093\/ije\/dyi274","article-title":"Evidence of bias in estimates of influenza vaccine effectiveness in seniors","volume":"35","author":"Jackson","year":"2006","journal-title":"Int. J. Epidemiol."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"201","DOI":"10.15585\/mmwr.mm7208a1","article-title":"Interim estimates of 2022\u201323 seasonal influenza vaccine effectiveness\u2014Wisconsin, October 2022\u2013February 2023","volume":"72","author":"McLean","year":"2023","journal-title":"MMWR Morb. Mortal. Wkly. Rep."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"135","DOI":"10.15585\/mmwr.mm6806a2","article-title":"Interim estimates of 2018\u201319 seasonal influenza vaccine effectiveness\u2014United States, February 2019","volume":"68","author":"Doyle","year":"2019","journal-title":"MMWR Morb. Mortal. Wkly. Rep."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"e0032624","DOI":"10.1128\/mbio.00326-24","article-title":"Estradiol mediates greater germinal center responses to influenza vaccination in female than male mice","volume":"15","author":"Dhakal","year":"2024","journal-title":"mBio"},{"key":"ref_28","unstructured":"Park, H.S., Yin, A., Zhou, W., Wenstedt, E.F.E., Jedlicka, A., Dziedzic, A., Fenstermacher , K.Z.J., Li, H., Shea, P.J., and Lee , J.S. (2025). Sex differences in B cell dynamics after seasonal influenza vaccination are dependent on the age and hormonal profile of vaccinees. medRxiv."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"169","DOI":"10.1016\/j.jinf.2013.05.004","article-title":"Cigarette smoking and mechanisms of susceptibility to infections of the respiratory tract and other organ systems","volume":"67","author":"Feldman","year":"2013","journal-title":"J. Infect."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Valeriani, F., Protano, C., Pozzoli, A., Vitale, K., Liguori, F., Liguori, G., and Gall\u00e8, F. (2024). Does tobacco smoking affect vaccine-induced immune response? A systematic review and meta-analysis. Vaccines, 12.","DOI":"10.3390\/vaccines12111260"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Eikenboom, A.M., Lambregts, M.M.C., de Boer, M.G.J., and le Cessie, S. (2024). Influence of initial misdiagnosis on mortality in patients with bacteraemia: Propensity score matching and propensity score weighting analyses. BMC Infect. Dis., 24.","DOI":"10.1186\/s12879-024-09299-9"}],"container-title":["Vaccines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-393X\/14\/7\/631\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T08:09:01Z","timestamp":1784534941000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-393X\/14\/7\/631"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,20]]},"references-count":31,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["vaccines14070631"],"URL":"https:\/\/doi.org\/10.3390\/vaccines14070631","relation":{},"ISSN":["2076-393X"],"issn-type":[{"value":"2076-393X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,20]]}}}