New preprint on the development of an improved blood-stage malaria vaccine

We are thrilled to announce that our latest preprint is available to read now on BioRxiv! The work, spearheaded by Barney Williams and Lloyd King, details the development of an improved malaria vaccines based on the essential RH5-CyRPA-RIPR (RCR) complex. 

We show that immunisation with the  RCR-complex consistently fails to outperform RH5.1 alone due to the immuno-dominance of RIPR coupled with the inferior potency of anti-full length RIPR polyclonal IgG antibodies. To address this, we identified that the growth-inhibitory antibody epitopes of RIPR are clustered within C-terminal EGF-like domains of RIPR. A fusion of these EGF domains to CyRPA, called “R78C” (below), combined with RH5.1, provided a new vaccination strategy that improves upon the levels of in vitro GIA seen with RH5.1 alone. Superiority of the combination antigen vaccine candidate was achieved by the induction of a quantitatively higher, but qualitatively similar, polyclonal antibody response that demonstrated additive GIA across the three antigen targets. These preclinical data justified the advancement of the RH5.1+R78C/Matrix-M™ combination vaccine to a Phase 1 clinical trial (ClinicalTrials.gov NCT05385471).