Evaluation and comparison of immune responses induced by two Mpox mRNA vaccine candidates in mice

Abstract

The epidemic of Mpox virus (MPXV) from May 2022 was once declared as a Public Health Emergency of International Concern by the World Health Organization. Vaccines play an important role in prevention of infectious diseases, and mRNA vaccine technology was proved to be a safe and effective platform with successful application in defense of coronavirus disease 2019. In this study, based on A29L, M1R, A35R, and B6R of MPXV, we developed two MPXV mRNA vaccine candidates, designated as MPXfus and MPXmix. The MPXfus was one‐component, in which these four antigen proteins were linked in tandem by flexible linker and encoded by an individual mRNA as a fusion protein. The MPXmix was multicomponent containing four mRNA, and each mRNA encoded one antigen protein respectively. Mice were immunized with equal quality of MPXfus or MPXmix, delivered by lipid nanoparticles for evaluation and comparison of the immune responses induced by these two MPXV vaccine candidates. Results of immune response analyses indicated that both MPXfus and MPXmix could elicit high‐level of antigen‐specific antibodies and robust cellular immune response in mice. Moreover, results of virus neutralization assays suggested that sera from MPXfus‐ or MPXmix‐immunized mice possessed high neutralizing activities against vaccinia virus. In addition, titers of antigen‐specific antibody, levels of cellular immune response, and activities of neutralizing antibody against vaccinia virus induced by MPXfus and MPXmix presented no significant difference. In summary, this study provides valuable insights for further clinical development of one‐component and multicomponent mRNA vaccine candidates for the prevention of MPXV and other orthomyxoviruses.

Longitudinal viral shedding and antibody response characteristics of men with acute infection of monkeypox virus: a prospective cohort study

“…Until recently, researchers have developed several mRNA vaccines and sub-unit vaccines based on different set of antigens 31,45,46,47,48,49,50,51 . Several surface proteins of MPXV, including M1R, E8L, H3L, A29L on the intracellular mature virion, A35R, and B6R proteins on the extracellular enveloped virion, has been found to be potential vaccine targets for MPVX 29 .…”

Breakthrough infection and reinfection in patients with mpox

“…Fortunately, several MPXV antigen‐specific mRNA vaccines are being developed, presenting high effectiveness in triggering immune responses and protecting mice from vaccina virus challenge 52–57 . Moreover, based on MPXV specific protective proteins, our team also developed one subunit vaccine and two mRNA vaccine candidates, all of which showed promising results in inducing cellular and humoral immune responses, as well as anti‐vaccinia virus activity in mouse model 58,59 …”

A cross-sectional investigation of factors influencing mpox vaccine hesitancy for students in Southwest China

“…Mpox is a zoonotic disease caused by mpox virus (MPXV) which is a large double‐stranded DNA virus and belongs to the Orthopoxvirus genus within the Poxviridae family. 1 , 2 The clinical manifestations of mpox are similar to those of smallpox, including pyrexia, back pain, headache, rash, malaise, and fatigue. 3 The complications of mpox may be even life-threatening, such as encephalitis, sepsis.…”