Naturally acquired antibody reactivity to two major Plasmodium vivax vaccine candidates was investigated in 294 donors from three malaria-endemic communities of Rondonia state, Brazil. Antibody recognition of recombinantly expressed antigens covering five different regions of P. vivax reticulocyte binding protein 1 (PvRBP1) and region II of P. vivax Duffy binding protein (PvDBP-RII) were compared. Positive IgG responses to these antigens were significantly related to the level of malaria exposure in terms of past infections and years of residence in the endemic area when corrected for age. The highest prevalence of anti-PvRBP1 total IgG antibodies corresponded to the amino acid regions denoted PvRBP1431-748 (41%) and PvRBP1 733-1407 (47%). Approximately one-fifth of positively responding sera had titers of at least 1:1,600. Total IgG responses to PvDBP-RII were more prevalent (67%), of greater magnitude, and acquired more rapidly than those to individual PvRBP1 antigens. Responses to both PvRBP1 and PvDBP-RII were biased toward the cytophilic subclasses IgG1 and IgG3. These data provide the first insights on acquired antibody responses to PvRBPl and a comparative view with PvDBP-RII that may prove valuable for understanding protective immune responses to these two vaccine candidates as they are evaluated as components of multitarget blood-stage vaccines.
|Original language||English (US)|
|Number of pages||12|
|Journal||American Journal of Tropical Medicine and Hygiene|
|State||Published - Aug 1 2005|
ASJC Scopus subject areas
- Infectious Diseases