Box plots for cytokine positive T cell frequencies on stimulation with CSP peptides pre-vaccination, 1 month after the last vaccination and 12 months after the last vaccination, shown by cytokine and by vaccination group.

<p>Box plots show medians and inter-quartile ranges, the whiskers show 5^th to 95^th centiles, and outliers are shown by circles. Vaccination group is indicated by “RTS” for RTS,S/AS01_E and “Ctl” for rabies control. T cell phenotype is indicated by + and − for the cytokines shown far left. Significance is indicated by a horizontal line at p<0.0003 (using a Bonferroni correction for multiple comparisons).</p

Kaplan Meier plot showing fraction of the RTS,S/AS01_E vaccinees experiencing an episode of clinical malaria, divided according to antibody and TNF+ only CD4+ cell anti-CSP responses.

<p>The 4 groups are as follows; 1) anti-CSP antibody titers below 40 EU/ml, TNF+ only CD4+ cells on CSP stimulation below median; 2) anti-CSP antibody titers above 40 EU/ml, TNF+ only CD4+ cells on CSP-peptide stimulation below median; 2) anti-CS antibody titers below 40 EU/ml, TNF+ CD4+ cells on CSP-peptide stimulation above median; 2) anti-CSP antibody titers above 40 EU/ml, TNF+ only CD4+ cells on CSP-peptide stimulation above median. The anti-CSP antibody titers are applied as a time-varying covariate.</p

A representative example of the identification and quantitation of RTS,S/AS01_E induced CSP-peptide reactive CD4+ T cells producing various cytokines.

<p>A) CD4+/CD8+ T cells were gated off the side scatter (SCC) Vs CD3 gate, after gating on lymphocytes on the SSC vs forward scatter (FSC) density plot. B) Determination of the percentages of IL2+, TNF+ and IFNγ CD4+ T cells following <i>in vitro</i> stimulations with nothing (Media control), CSP and SEB. C) An example of a typical gating tree showing the identification and quantitation of CD4+ T cells producing various combinations of IL2, TNF and IFNγ, following stimulation with nothing (media control), CSP or SEB, is shown. The resultant data was expressed as percentages of cytokine positive CD4+ T cells.</p

Multivariable logistic regression analysis for the effect avidity on clinical malaria.

<p>Multivariable logistic regression analysis for the effect avidity on clinical malaria.</p

Geometric means and 95% confidence intervals for cellular responses to CSP by vaccination group and t-test on log-transformed values for significance of difference.

<p>Pre-vac = prior to vaccination, Vac+1 = 1 month after final vaccination, Vac+12 = 12 months after final vaccination.</p

Hazard Ratios (HR) and 95% Confidence intervals from Cox regression models for the effect of CD4+ cellular responses to CSP on clinical malaria episodes.

<p>Hazard Ratios are adjusted by age (as a continuous variable), distance from the dispensary (continuous variable), bednet use, location of residence (in 4 groupings) and, when all vaccinees are included in an analysis, by vaccination group.</p><p>“At least TNF+” refers to all cells producing TNF, including polyfunctional cells (i.e. producing TNF with IL2, TNF with IFNγ, or TNF with IFNγ and IL2). The parallel definition applies to “at least IL2+”. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0052870#s2" target="_blank">Results</a> that are significant after a Bonferroni correction (i.e.<0.002) are shown in bold.</p

Box plot of anti-CS antibody avidity by level of malaria exposure (based on malaria exposure index) at 1, ∼8 and 12 months post dose 3.

<p>Box plot of anti-CS antibody avidity by level of malaria exposure (based on malaria exposure index) at 1, ∼8 and 12 months post dose 3.</p

Avidity indices in cases, controls and a subset of 19 controls with high exposure rates and low anti-CS titers at different sampling times.

<p><i>CI: Confidence Intervals.</i></p><p><i>*p value for the comparison between cases and controls (all).</i></p><p>Avidity indices in cases, controls and a subset of 19 controls with high exposure rates and low anti-CS titers at different sampling times.</p

Panel A: Anti-CS titers in cases, controls and 19 protected children with low anti-CS antibodies titer and high malaria exposure index during 15 months of follow-up.

<p>Panel B: Matrix diagram showing correlation between antibody avidity measured at three time points during the follow up. Significant correlation observed between AI at 1 month post-dose 3 and at ∼8 months post-dose 3 (r = 0.33, p value = 0.0111) and at 1 month and 12 months post-dose 3 (r = 0.48, p value = 0.0002). Panel C: Correlation between anti-CS antibody avidity at 1 month post dose 3 and age (r = 0.003, p value = 0.656) Panel D: Correlation between anti-CS antibody avidity and anti-CS antibody titers at 1 month post dose 3 (r = –0.03; p value = 0.859).</p

Percentage of subjects with growth inhibition assay activity ≥15% against FVO parasites, and percentage seroconverting from below up to or above threshold 30 days after last vaccination and at one and two years after enrollment, by vaccine group.

<p>Percentage of subjects with growth inhibition assay activity ≥15% against FVO parasites, and percentage seroconverting from below up to or above threshold 30 days after last vaccination and at one and two years after enrollment, by vaccine group.</p