Abstract
Enterovirus 71 (EV71) is an etiologic agent responsible for seasonal epidemics of hand-foot-and-mouth disease and causes outbreaks with significant mortality in child under 5 years of age, but there is no effective vaccine for EV71. Our group has previously demonstrated that EV71 virus-like particles (VLP) produced from the baculovirus/insect cell system induce high antibody titers in animal models and protect animals from virus infection, suggesting that VLPs are a good EV71 vaccine candidate. In this study, we aimed to investigate and improve the stability of EV71 VLPs. We first established the characterization methods including Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM) and Enzyme-Linked Immunosorbent Assay (ELISA) to evaluate the VLPs stability and further examined the parameters that influence the VLPs stability, including buffer, temperature and stabilizer. The data demonstrated that the shape, size and immunogenicity of VLPs remained stable when stored in the buffers used in the VLPs production and purification processes. The VLPs also remain stabled when upon storage in sodium phosphate buffer (pH 6.5) at 4□C for 5 months. These data collectively confirm that VLPs are reasonably stable and implicate the potentials of EV71 VLPs as a vaccine product.