Fig. 3

EV71 antigen stimulated specific IFN-γ and IL-4 responses in peripheral blood mononuclear cells from volunteers immunized with either the vaccine or placebo. Blood samples from 40 participants from among the 350 subjects who provided a full series of blood samples within the 2-year follow-up period were obtained at 720 days after immunization to evaluate IFN-γ and IL-4 production. These children were 6–11 months old (a) (five individuals in the vaccine group and five in the placebo group), 12–23 months old (b) (five individuals in the vaccine group and five in the placebo group), 24–35 months old (c) (five individuals in the vaccine group and five in the placebo group), and 36–71 months old (d) (five individuals in the vaccine group and five in the placebo group). The mean levels of cytokines are shown above the bar