IGHG3 and malaria: However, in children < 5 years of age, increasing levels of IgG and IgG1 antibodies against GLURP-R2 (adjusted odds ratio (aOR) [95% confidence interval (CI)], 0.51 [0.29, 0.89] and 0.33 [0.16, 0.70], respectively), and IgG and IgG3 against MSP-2 (0.49 [0.27, 0.87] and 0.46 [0.23, 0.93], respectively), were associated with a decreased risk of clinical malaria (Fig. 3).