Safety Comparison of Two Enterovirus 71 (EV71) Inactivated Vaccines in Yiwu, China

The safety of two kinds of post-marketing enterovirus 71 (EV71) vaccine in China was evaluated in this study. Fourteen vaccination clinics were randomly assigned in a 1:1 ratio, and both children in two groups were administered according to a two-dose schedule (on a 0 and 28 day schedule). Written informed consent was obtained, and recipients in this study were observed for 30 min after inoculation in the clinic, and then followed via phone or on-site follow-up at day 3 and 30. No severe EV71-associated adverse event was reported. No significant difference was noticed between Group Sinovac and Group CAMS (χz = 0.346, p = 0.556). There was no significant difference in the occurrence of adverse events among recipients aged less than 24 months; however, the proportion of adverse events was higher in Group CAMS than in Group Sinovac among the subjects aged 24-35 months (5.3% vs. 2.5%, p < 0.001). The two kinds of EV71 vaccines showed satisfactory safety. Adverse events after vaccination were normal and acceptable.