Background: Completion of the full series of childhood vaccines on-time is crucial to ensuring greater protection against vaccine-preventable diseases.Aim: To examine determinants of complete and on-time vaccination and evaluate the relationship between vaccination patterns and severe morbidity outcomes.Subjects and methods: Vaccination information from infants in Nairobi Urban Health and Demographic Surveillance System was used to evaluate full and on-time vaccination coverage of routine immunisation. Logistic regression was used to identify determinants of full and on-time vaccination coverage. Cox regression model was used to evaluate the relationship between vaccination status and subsequent severe morbidity. A shared frailty cox model was fitted to account for the heterogeneity in hospitalisation episodes.Results: Maternal age, post-natal care, parity, ethnicity, and residence place were identified as determinants of vaccination completion. Institutional deliveries and residence place were identified as the determinants of on-time vaccination. A significant 58% (confidence interval [CI]: 15-79%) (p = .017) lower mortality was observed among fully immunised children compared with not fully immunised. Lower mortality was observed among on-time immunised children, 64% (CI: 20-84%) compared to those with delays.Conclusions: Improving vaccination timeliness and completion schedule is critical for protection against vaccine preventable diseases and may potentially provide protection beyond these targets.

中文翻译：

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定期按时完成常规的儿童免疫接种：肯尼亚内罗毕的城市非正规住区的决定因素和与严重发病率的关系。

背景：按时完成全套儿童疫苗对于确保更好地预防可预防疫苗的疾病至关重要。目的：检查完整和按时接种疫苗的决定因素，并评估疫苗接种方式与严重发病率之间的关系。方法：内罗毕城市卫生和人口统计学监测系统中的婴儿疫苗接种信息用于评估常规免疫的全部和及时疫苗接种覆盖率。Logistic回归用于确定全面和按时接种疫苗覆盖率的决定因素。使用Cox回归模型评估疫苗接种状况与随后的严重发病率之间的关系。拟合了一个脆弱的共享cox模型以说明住院期间的异质性。结果：产妇年龄，产后护理，均等，种族和居住地被确定为疫苗接种完成的决定因素。机构分娩和居住地被确定为及时接种疫苗的决定因素。与未完全免疫的儿童相比，完全免疫的儿童死亡率降低了58％（可信区间[CI]：15-79％）（p = .017）。与按时延误的儿童相比，按时免疫的儿童的死亡率较低，为64％（CI：20-84％）。结论：改善疫苗及时性和完成时间表对于预防疫苗可预防的疾病至关重要，并且可能提供除这些以外的保护措施目标。机构分娩和居住地被确定为及时接种疫苗的决定因素。与未完全免疫的儿童相比，完全免疫的儿童死亡率降低了58％（可信区间[CI]：15-79％）（p = .017）。与按时延误的儿童相比，按时免疫的儿童的死亡率较低，为64％（CI：20-84％）。结论：改善疫苗及时性和完成时间表对于预防疫苗可预防的疾病至关重要，并且可能提供除这些以外的保护措施目标。机构分娩和居住地被确定为及时接种疫苗的决定因素。与未完全免疫的儿童相比，完全免疫的儿童死亡率降低了58％（可信区间[CI]：15-79％）（p = .017）。与按时延误的儿童相比，按时免疫的儿童的死亡率较低，为64％（CI：20-84％）。结论：改善疫苗及时性和完成时间表对于预防疫苗可预防的疾病至关重要，并且可能提供除这些以外的保护措施目标。