Antibodies to the 4-mer repeat of the ring-infected erythrocyte surface antigen (Pf155/RESA) protect against Plasmodium falciparum malaria.

To investigate the protective role of antibodies to the ring-infected erythrocyte surface antigen (Pf155/RESA) epitopes against Plasmodium falciparum clinical malaria, a cohort study was conducted in a Malagasy village over 7 months. In the 304 individuals included, 127 experienced P. falciparum attacks of under 1500 parasites/microliters with no clinical symptoms (protected individuals) and 177 experienced at least one clinical or preclinical P. falciparum attack requiring therapy (unprotected individuals). Antibodies to whole Pf155/RESA, to single epitopes of the 3' terminus, (EENV)4 and EENVEHDA(EENV)2 had higher responses in protected than in unprotected individuals (P = 0.006, P = 0.005, P = 0.05 respectively). Within the whole pattern of antibodies to the Pf155/RESA epitopes, only anti-R4 was related to protection independently of age and anti-wR. The Pf155/RESA 4-mer repeated epitope might be of interest for inclusion in a vaccine against the asexual blood stages of P. falciparum.