The dichotomy (generation of MAbs with functional heterogeneity) in antimalarial immune response in vaccinated/protected mice: a new concept in our understanding of the protective immune mechanisms in malaria.

Globally, vaccines have emerged as one of the most effective, safe, and cost-effective public health interventions, and are known to save 2–3 million lives, annually. However, despite various commendable efforts, a suitable human malaria vaccine is yet to see the light of the day. The lack of our complete understanding of the molecular mechanisms of pathogenesis and immune protection in malaria appears to be responsible for this state. Earlier, our laboratory has reported that Swiss mice vaccinated with Plasmodium yoelii nigeriensis-total parasite antigens soluble in culture medium and saponin, following a 100% lethal challenge, showed 60% protection. The monoclonal antibodies (MAbs) generated from the splenocytes of these vaccinated/protected mice, following characterization by in vitro merozoite invasion inhibition assay, ex vivo macrophage phagocytosis assay, and in vivo passive transfer of protection test, belonged to 2 distinct groups—a larger group of MAbs inhibited <58% Mz invasion and transferred ...