IGHG3 and malaria: IgM and IgG3 both enhance antibody responses via the complement system, but may complement each other regarding which types of antigen they prefer: IgM enhances antibody responses to large antigens such as erythrocytes, malaria parasites, and KLH, while IgG3 enhances responses to small proteins like OVA and BSA, and, as shown herein, also to KLH.