Development of a novel EV-A71 monoclonal antibody for monitoring vaccine potency

Enterovirus A71 (EV-A71) is one of the major causes of hand, foot, and mouth disease (HFMD), primarily affecting children under five. It can lead to neurological and cardiac complications, or even death, in some cases. Inactivated monovalent vaccines have been licensed in China and Taiwan; however, the stability of EV-A71 vaccines is often compromised by factors such as extreme temperatures or ultraviolet (UV) irradiation. Currently, no commercially available tools can assess the stability of EV-A71 throughout vaccine development. In this study, we report the development of a monoclonal antibody (mAb), NHRI2016-1, which can be used in in vitro immunoassays to evaluate EV-A71 vaccine potency and effectiveness. NHRI2016-1 exclusively recognizes effective EV-A71 antigens in in vitro potency assays. Similarly, rat experiment confirmed that effective vaccine antigens could induce neutralizing antibodies, while ineffective antigens could not. Thus, NHRI2016-1 shows potential for correlating in vitro potency with in vivo immunogenicity of EV-A71 vaccine antigens. These data suggest that NHRI2016-1 could be a promising tool for characterizing EV-A71 vaccines and monitoring vaccine potency.