A Follow-up Study for a Phase III, Efficacy Trial in Inactivated Enterovirus Type 71 (EV71) Vaccine

An Open-labelled, Multicentered, Follow-up Study for a Phase III, Efficacy Trial to Evaluate the Two-year Efficacy, Safety, and Immune Persisitence of Inactivated Enterovirus Type 71 (EV71) Vaccine

The purpose of this follow-up study is to evaluate the two-year efficacy, immunogenicity and safety of EV71 Vaccines in preventing Hand, Foot and Mouth disease caused by EV71 in a total 10,000 healthy infants volunteers aged from 6 to 35months old.

The phase III, efficacy trial of inactivated vaccine (vero cell) against EV71 has completed on March 2013 in China. The data from the phase III study suggested that the inactivated EV71 vaccine had protection effects on healthy Chinese infants against Hand, Foot and Mouth disease caused by EV71 within one-year surveillance period, and had clinically acceptable safety and good one-year immune persistence.

This study is the phase III, open-labelled, follow-up research, in order to evaluate the two-year efficacy, safety and immune persistence.

Inclusion Criteria:

• All subjects vaccinated at least one injection of EV71 vaccine or the placebo in the phase III efficacy trial.

Exclusion Criteria:

• subjects who refuse to continue in the study.