IGHG3 and malaria: However, site-specific analysis of the different IgG subclasses revealed no significant difference between children positive and negative for clinical malaria for IgG1 and IgG3 in Bamenda (in the HWP strata) and Limbe (in the C strata), and for all the IgG subclasses in Maroua (in the SS strata), suggesting that infection is required to mount an effective immune response against the malaria parasite.