Centre for Safe Medication Practice and Research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China; Laboratory of Data Discovery for Health (D²4H), Hong Kong, China.
Centre for Safe Medication Practice and Research, Department of Pharmacology and Pharmacy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong, China; Department of Medicine, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong; Laboratory of Data Discovery for Health (D²4H), Hong Kong, China.
Vaccine. 2021 May 6;39(19):2628-2635. doi: 10.1016/j.vaccine.2021.03.090. Epub 2021 Apr 12.
Nine years after the introduction of pneumococcal conjugate vaccine (PCV) in the United States, Hong Kong (HK) introduced the vaccine to its universal childhood immunisation programme in 2009. We aimed to assess the impact of childhood PCV immunisation on all-cause pneumonia (ACP) admissions among the overall population of HK.
In this population-based interrupted time series analysis, we used territory-wide population-representative electronic health records in HK to evaluate the vaccine impact. We identified hospitalised patients with a diagnosis of pneumonia from any cause between 2004 and 2017. We applied segmented Poisson regression to assess the gradual change in the monthly incidence of ACP admissions between pre- and post-vaccination periods. Negative outcome control, subgroup and sensitivity analyses were used to test the robustness of the main analysis.
Over the 14-year study period, a total of 587,607 ACP episodes were identified among 357,950 patients. The monthly age-standardised incidence of ACP fluctuated between 33.42 and 87.44 per 100,000-persons. There was a marginal decreasing trend in pneumonia admissions after PCV introduction among overall population (incidence rate ratio [IRR]: 0·9965, 95% confidence interval [CI]: 0·9932-0·9998), and older adults (≥65 years, IRR: 0·9928, 95% CI: 0·9904-0·9953) but not in younger age groups.
There was a marginally declining trend of overall ACP admissions in HK up to eight years after childhood PCV introduction. The significance disappeared when fitting sensitivity analyses. The results indicate the complexities of using non-specific endpoints for measuring vaccine effect and the necessity of enhancing serotype surveillance systems for replacement monitoring.
Health and Medical Research Fund, Food and Health Bureau of the Government of Hong Kong (Reference number: 18171272).
在美国引入肺炎球菌结合疫苗（PCV）九年后，中国香港（香港）于 2009 年将该疫苗纳入其儿童常规免疫计划。我们旨在评估儿童 PCV 免疫接种对香港总人口中所有原因肺炎（ACP）入院的影响。
在这项基于人群的中断时间序列分析中，我们使用香港全领土人口代表性电子健康记录来评估疫苗的影响。我们确定了 2004 年至 2017 年期间因任何原因住院的肺炎患者。我们应用分段泊松回归评估疫苗接种前后期间 ACP 入院每月发病率的逐渐变化。负面结果对照、亚组和敏感性分析用于测试主要分析的稳健性。
在 14 年的研究期间，共在 357950 名患者中确定了 587607 例 ACP 发作。ACP 的每月年龄标准化发病率在 33.42 至 87.44 之间每 100000 人。在 PCV 引入后，总人口（发病率比 [IRR]：0.9965，95%置信区间 [CI]：0.9932-0.9998）和老年人（≥65 岁，IRR：0.9928，95%CI：0.9904-0.9953）中，肺炎入院率呈略有下降趋势，但在年轻年龄组中则不然。
在儿童 PCV 引入后长达八年的时间里，香港的总体 ACP 入院率呈略有下降趋势。当拟合敏感性分析时，这种趋势消失了。结果表明，使用非特异性终点来衡量疫苗效果的复杂性，以及增强替代监测的血清型监测系统的必要性。
香港特别行政区政府卫生署食物及卫生局（参考号：18171272）。
