Objective To investigate the expression of vasoactive intestinal peptide(VIP) in peripheral blood of children with hand, foot and mouth disease and its significance. Methods According to the condition of the disease, 86 children with hand, foot and mouth disease were classified into phase 1 group(19 children) and phase 2 group(67 children). ELISA was used to measure the concentrations of plasma VIP, interferon-γ(IFN-γ), and interleukin-4(IL-4) in peripheral blood. Flow cytometry was used to measure CD3~+, C...