IGHG3 and malaria: Positive serum IgG levels to several different P. falciparum blood stage antigens, such as merozoite surface proteins (MSP1-19, MSP1 block 2, MSP2), apical membrane antigen (AMA1) and erythrocyte binding antigen (EBA175), have been shown to be associated with reduced incidence of malaria in prospective cohort studies and where the subclass has been investigated, it is cytophilic and complement fixing IgG1 and IgG3 subclasses that are most strongly associated with protection (11–31).