苏州地区b型流感嗜血杆菌结合疫苗对减少儿童住院肺炎有效性的观察性研究

  目的  评价接种不同剂次b型流感嗜血杆菌(Haemophilus influenzae type b, Hib)结合疫苗对儿童住院肺炎的保护效果(vaccine effectiveness, VE)。  方法  采用回顾性队列研究设计，以2018年出生并在苏州大学附属儿童医院住院的苏州地区常住儿童为研究对象，分别通过苏州大学附属儿童医院卫生信息系统和苏州市疾病预防控制中心疫苗登记数据库收集研究对象在2019年6月30日之前因肺炎住院的相关医疗信息以及Hib疫苗接种信息，比较不同剂次Hib疫苗接种组和未接种组的住院肺炎发生率，计算Hib疫苗保护效果。  结果  2018年1月1日-2019年6月30日苏州地区儿童Hib疫苗的首剂接种率为18.8%(10 080/53 753)；住院肺炎发生率随接种剂次的增加而降低(χ2=-4.31, P < 0.001)，其中1剂次Hib疫苗未显示保护效果，2剂次Hib疫苗已显示出保护趋势，但差异无统计学意义，接种3剂次及以上Hib疫苗的儿童住院肺炎发生率低于未接种组(RR=0.72, 95% CI: 0.59~0.89, P＜0.001)，且可预防的住院肺炎发生率为1 514.8/105人年，保护效果为28%(95% CI: 11%~41%)。  结论  苏州地区3剂次及以上Hib疫苗接种可降低儿童因肺炎住院的发生率，建议推广儿童Hib疫苗接种工作，提高Hib疫苗覆盖率。

Effectiveness of Haemophilus influenzae type b conjugate vaccine on hospitalized pneumonia among children in Suzhou: an observational study

Objective To evaluate the vaccine effectiveness(VE) of different doses of Haemophilus influenzae type b(Hib) conjugate vaccine on hospitalized pneumonia among children. Methods A retrospective cohort study was conducted among local children born in 2018 and admitted to Suzhou University Affiliated Children’s Hospital. Hospital records were collected by using Hospital Information System and vaccination information were identified through Suzhou CDC’s electronic vaccine registry database before Jun 30, 2019. The incidence rates of hospitalized pneumonia among vaccinated and children with different doses unvaccinated children were compared and VE was calculated. Results Hib vaccination coverage of ≥1-dose was 18.8%(10 080/53 753)among children in Suzhou between Jan 1, 2018 to Jun 30, 2019. The incidence rates of hospitalized pneumonia decreased with the increase of doses of Hib vaccine(χ²=-4.31, P<0.001), and the protective effects of 1-dose and 2-doses Hib vaccine were not found, but 2-doses Hib vaccine showed a trend of protection. The incidence rate of hospitalized pneumonia among children who received ≥3-doses Hib vaccine was lower than unvaccinated children(RR=0.72, 95% CI: 0.59-0.89, P<0.001), and the incidence rate of vaccine-preventable hospitalized pneumonia was 1 514.8 per 10~5 person-years, and VE of ≥3-doses was 28%(95% CI: 11%-41%). Conclusions Incidence rate of hospitalized pneumonia among children in Suzhou can be reduced by ≥3-doses Hib vaccination. It is suggested that Hib vaccination should be further promoted in children to increase the Hib vaccination coverage.