Fig. 4: Neutrophil-phagocytosis of merozoites is dominant compared to monocytes and predicts protection against febrile malaria.

Paired aligned dot plots coupled to box and whiskers plots showing the number of EtBr-positive neutrophils and monocytes present in PBLs from Danish blood donors which were used as effector cells to test the phagocytosis mediating ability of antibodies present in Ghanaian a and Indian c cohort plasma samples. Both the Ghanaian children (n = 140; protected = 59, susceptible = 81) b and the Indian participants (n = 121; protected = 71, susceptible = 50) d were categorized into two equal groups based on the median phagocytosis values obtained with neutrophils or monocytes, and the risk of encountering febrile malaria during the follow-up periods was calculated with Cox-regression models comparing those with high versus low (reference group) phagocytosis. Values represent age-adjusted (filled triangles) and unadjusted (filled squares) hazard ratios with 95% confidence intervals. Boxes indicate the median and interquartile range. Whiskers mark the minimum and maximum values. P values were determined by Wilcoxon signed-rank test a and c. Asterisks represent P values (****P < 0.0001).