Post-marketing evaluation of the effectiveness and safety of a varicella attenuated live vaccine in China

Objective To evaluate the effectiveness and safety of varicella attenuated live vaccine (VarV) produced by A Co. Ltd. Methods We selected 3 provinces in China and enrolled 15 002 children aged 3-<11 in this random, multicenter study. Participants were randomly divided into two groups: the experimental group and the control group. Every varicella case was collected and recorded to calculate the vaccine efficacy. Vaccine safety was assessed by means of spontaneous report and regular follow-up visits. Results During the observation period, the incidence of varicella was 0.147% in the experimental group and 1.155% in the control group (P<0.001). The vaccine efficacy was 87.27%. The adverse reaction rate after vaccination was lower than the rates reported in other literatures. Conclusion The VarV produced by A Co., Ltd. in China was effective and safe in preventing varicella. Key words: Varicella attenuated live vaccine; Multicenter study; Vaccine efficacy; Vaccine safety