Evaluating the potential of cross-species neutralization of anti-PfCyRPA and anti-PfRIPR monoclonal antibodies

PfCyRPA and PfRIPR are promising next-generation blood-stage vaccine
candidates that play a crucial role in erythrocyte invasion of Plasmodium
species. CyRPA and RIPR orthologs are present in all human-infecting
Plasmodium species, suggesting the potential for a cross-species vaccine.
Using Growth Inhibition Assays (GIA), this study investigates seven
anti-PfCyRPA and three anti-PfRIPR monoclonal antibodies targeting P.
falciparum for their inhibitory activity against P. knowlesi, a
non-falciparum species that contributes to a significant burden of disease
in South Asia, shares some biological features with Plasmodium vivax,
 and has a robust in vitro culture system. Despite their efficacy
against P. falciparum and partially conserved epitopes, these antibodies
exhibited minimal inhibition of P. knowlesi. Understanding the antigenic
diversity and immune mechanisms across Plasmodium species is critical for
advancing pan-species vaccine strategies.