Abstract:
The Enterovirus A71 (EV-A71) vaccine was introduced in China in December 2015 as a preventive measure against hand, foot, and mouth disease (HFMD) caused by EV-A71. However, the effectiveness of the vaccine (VE) in real-world settings needs to be evaluated. We conducted a test-negative case-control study to assess the effectiveness of EV-A71 vaccines in preventing EV-A71-associated HFMD. Children aged 6-71 months with HFMD were enrolled as participants. The case group comprised those who tested positive for EV-A71, while the control group comprised those who tested negative for EV-A71. To estimate VE, a logistic regression model was employed, adjusting for potential confounders including age, gender, and clinical severity. In total, 3223 children aged 6 to 71 months were included in the study, with 162 in the case group and 3061 in the control group. The proportion of children who received EV-A71 vaccination was significantly lower in the case group compared to the control group (p < .001). The overall VEadj was estimated to be 90.8%. The VEadj estimates for partially and fully vaccinated children were 90.1% and 90.9%, respectively. Stratified by age group, the VEadj estimates were 88.7% for 6 to 35-month-olds and 95.5% for 36 to 71-month-olds. Regarding disease severity, the VEadj estimates were 86.3% for mild cases and 100% for severe cases. Sensitivity analysis showed minimal changes in the VE point estimates, with most changing by no more than 1% point. Our study demonstrates a high level of vaccine effectiveness against EV-A71-HFMD, especially in severe cases. Active promotion of EV-A71 vaccination is an effective strategy in preventing EV-A71 infections.
摘要:
肠道病毒A71(EV-A71)疫苗于2015年12月在中国推出,作为预防手,脚,和由EV-A71引起的口蹄疫(HFMD)。然而,需要评估疫苗(VE)在现实环境中的有效性.我们进行了一项测试阴性病例对照研究,以评估EV-A71疫苗预防EV-A71相关HFMD的有效性。6-71个月的手足口病患儿作为参与者。病例组包括EV-A71测试阳性的人,而对照组包括EV-A71测试阴性的人。要估计VE,采用逻辑回归模型,调整潜在的混杂因素,包括年龄,性别,和临床严重程度。总的来说,3223名6至71个月的儿童被纳入研究,病例组162例,对照组3061例。病例组接受EV-A71疫苗接种的儿童比例明显低于对照组(p<.001)。总体VEadj估计为90.8%。部分和完全接种疫苗的儿童的VEadj估计为90.1%和90.9%,分别。按年龄组分层,VEadj估计6至35个月儿童为88.7%,36至71个月儿童为95.5%。关于疾病的严重程度,VEadj估计轻度病例为86.3%,重度病例为100%.敏感性分析显示VE点估计的变化最小,大多数变化不超过1%。我们的研究表明,针对EV-A71-HFMD的疫苗有效性很高,特别是在严重的情况下。积极促进EV-A71疫苗接种是预防EV-A71感染的有效策略。