Matrix-M + RH5.2 VLP + R21

Matrix-M + RH5.2 VLP + R21 is an investigational multi-component malaria vaccine candidate that combines three elements: - **Matrix-M** is a saponin-based adjuvant developed by Novavax, designed to enhance the immune response to co-administered antigens. - **RH5.2 VLP** refers to a virus-like particle (VLP) displaying a thermostabilized and engineered version of the *Plasmodium falciparum* reticulocyte-binding protein homolog 5 (PfRH5), which is essential for erythrocyte invasion during the blood stage of malaria infection. The RH5.2 antigen has been optimized for stability and immunogenicity, and its presentation on hepatitis B surface antigen VLPs via “plug-and-display” technology induces robust growth-inhibitory antibodies[1][6]. - **R21** is a recombinant protein vaccine targeting the circumsporozoite protein (CSP) of *P. falciparum*, fused to hepatitis B surface antigen particles, also formulated with Matrix-M adjuvant[3][4]. This combination aims to provide both pre-erythrocytic (liver stage) protection via R21/CSP and blood-stage protection via RH5.2, potentially offering broader efficacy than single-antigen vaccines like RTS,S/AS01 or R21/Matrix-M alone[1][4]. The approach seeks to induce strong antibody responses against multiple stages of the parasite’s lifecycle. The combination is currently under early-phase clinical investigation for safety, immunogenicity, and efficacy in children in malaria-endemic regions[4].