The data from the phase I and II study suggested that the inactivated EV71 vaccine (vero cell) had a clinically acceptable safety and good immunogenicity for healthy Chinese infants. The phase III study of inactivated vaccine has initiated on Jan 2012 in China. Over 10,000 healthy infants have revieved the vaccines and no unexpected severe adverse reactions were reported. According to the requirement of SFDA (China), the sponsor should also provide the evidence for the consistency of three consecutive lots of EV71 Vaccines before the application for the market. Thus, a clinical trial to evaluate the immunogenicity and safety of three consecutive lots of EV71 Vaccines in healthy infants volunteers is planed to conduct.
The purpose of this study is to evaluate the immunogenicity and safety of three consecutive lots of EV71 Vaccines in healthy infants volunteers aged from 6 months to 5 years old.