<i>P. vivax</i> erythrocytic antigen specific IgM and IgG subclass profiles among different Duffy genotypes.

<p>IgM and IgG subclass among Fy+ donors that had total IgG against PvMSP1 and PvDBP was measured by ELISA to determine the frequencies (A) and magnitude (B) of responses against PvMSP1 and PvDBP. IgM and IgG subclass against PvMSP1 and PvDBP were also compared among donors with different Duffy genotypes (C). Samples are considered positive when the OD reading is > average OD of naïve controls + 3SD for frequency of responses or index of reactivity (IR) is greater than 1 for the magnitude of responses, respectively.</p

Broad antibody responses against malaria were induced by natural exposures in Colombia.

<p>We assessed malaria antigen-specific antibody responses in 233 donors living in Caribbean coast town (Apartado and Turbo) of Colombia. One hundred thirty nine (60%) donors had antibodies against at least one of five malaria antigens examined. Numbers represent the responders who had antibodies against both <i>P. vivax</i> and/or <i>P. falciparum</i> antigens (A), different <i>P. vivax</i> antigens, PvCSP, PvMSP1, PvDBP (B), or different <i>P. falciparum</i> antigens PfCSP and PfMSP1 (C).</p

The levels of antibody responses against <i>P. vivax</i> erythrocytic antigens differ among different Duffy genotypes.

<p>Immune recognition of <i>P. vivax</i> sporozoite antigen (A: PvCSP) and blood stage antigens (B: PvMSP1, C: PvDBP), or <i>P. falciparum</i> sporozoite antigen (D: PfCSP) and blood stage antigen (E: PfMSP1) by sera of donors with different Duffy genotypes FY*A/FY*B (A/B), FY*A/FY*Bnull (A/Bnull), FY*B/FY*B (B/B) and FY*B/FY*Bnull (B/Bnull). Values are expressed as Index of Reactivity (IR) that is calculated as test OD divided by cut-off OD. The cut-off OD is the average OD value of US donors (with no prior exposure to malaria)+3 SD. The IR of donors with FY*A/FY*B genotype is compared with those of FY*A/FY*Bnull, and FY*B/FY*B with FY*B/FY*Bnull using Student's <i>t</i>-test and <i>p</i> values<0.05 were considered significant.</p

Immune recognition of different <i>P. vivax</i> and <i>P. falciparum</i> stage-specific antigens.

<p>Antigen-specific total IgG in sera of the donors living in malaria-endemic regions of Colombia (Apartado and Turbo) were assessed by ELISA against <i>P. vivax</i> circumsporozite protein (PvCSP), blood stage antigens (PvMSP1, <i>Pv</i>DBP), <i>P. falciparum</i> circumsporozoite protein (PfCSP) and blood stage antigen (PfMSP1). A sample is considered positive if the index of reactivity (IR) is greater or equal to 1. IR is calculated as the average OD of sample divided by the cut-off OD with the cut of OD being the sum of average OD values of US donors (with no prior exposure to malaria) + 3 standard deviations. Listed are the mean and SD of the IR, the number and percentage of positive samples (#Pos (%)), <i>P value</i>s were caulcated by Chi-squared test.</p

Antibody responses against <i>P. vivax</i> erythrocytic antigens are significantly greater in Fy+ than in Fy− individuals.

<p>Immune recognition of <i>P. vivax</i> sporozoite antigen (A: PvCSP) and blood stage antigens (B: PvMSP1, C: PvDBP), or <i>P. falciparum</i> sporozoite antigen (D: PfCSP) and blood stage antigen (E: PfMSP1) by sera of Fy+) and Fy− donors were assessed by ELISA. Values are expressed as Index of Reactivity (IR) that is calculated as test OD divided by cut-off OD. The cut-off OD is the average OD value of US donors (with no prior exposure to malaria)+3 SD.</p