ABSTRACT
Objective To investigate the vaccine efficacy (VE) of two doses of inactivated enterovirus 71 (EV71) vaccine on severe hand, foot, and mouth disease (HFMD) in eligible children. Methods A retrospective case-control study was conducted in this project. A total of 109 patients with EV71 severe HFMD aged between 6 months to 5 years old who were admitted to the Pediatric Intensive Care Unit (PICU) of Guangxi Maternity and Child Health Hospital from September 2016 to September 2020, and reported to the Chinese Disease Prevention and Control Information System were selected as the case group. According to 1:1 matching,109 healthy children aged between 6 months to 5 years old were selected as the control group. The vaccine efficacy of EV71 inactivated vaccine was calculated. Results The vaccination rate of the two doses of inactivated EV71 vaccine in the case group was significantly lower than that in the control group（9.17% to 54.13%，χ2=50.911, P<0.05；OR=0.086(95%CI:0.040-0.182)). The vaccine efficacy of two doses of inactivated EV71 vaccine was 91.44% (95% CI:81.8%-96%). Conclusion The inactivated EV71 vaccine has a good protective effect on hand, foot, and mouth disease caused by EV71. The vaccination of EV71 inactivated vaccine should be continuously promoted.