Fig. 3

P. falciparum-specific CD4⁺ T cell proliferation enhanced after period of minimal exposure. Proportion of P. falciparum-specific CD4⁺ T cells proliferating in response to iRBC stimulation is significantly higher in children with little current exposure to malaria (Blue dots, Ngerenya, n = 37) compared to continually exposed children (Red squares, Junju, n = 37) and malaria-naïve children (Black triangles, n = 8). P. falciparum-specific proliferation was calculated as percentage of CFSE-lo CD4⁺ T cells following iRBC stimulation minus uRBC stimulation. Non-specific CD4⁺ T cell proliferation in response to plate-bound anti-CD3 stimulation was also compared across the three groups. Statistically significant P values (P < 0.05) are indicated by asterisk (in red for Kruskal–Wallis or black for Mann–Whitney U-tests, respectively)