An MPXV mRNA-LNP vaccine candidate elicits protective immune responses against monkeypox virus

The monkeypox virus (MPXV) outbreak, declared a Public Health Emergency of International Concern (PHEIC) by the World Health Organization (WHO) in 2022, continues to pose a significant threat due to the absence of vaccines or drugs for MPXV infection. In this study, we developed an mRNA vaccine that expressing the A29L antigen, a specific protein of the intracellular mature virus. Our vaccine utilizes a thermostable ionizable lipid nanoparticle (iLNP) platform and has been administered to mice. Our findings demonstrate that the MPXV A29L mRNA vaccine candidate induces robust cross-neutralizing immune responses against both vaccinia virus (VACV) and MPXV live virus. Furthermore, immunization with the vaccine candidate provided protection against the VACV challenge in mice. These findings underscore the potential of mRNA-LNP vaccines as safe and effective candidates against monkeypox epidemics. Given the current absence of specific interventions for MPXV infection, our study represents a significant step forward in developing a viable solution to combat this ongoing public health threat.