IGHG3 and malaria: However, the tendency for malaria cases to be associated with higher levels of IgG3 and lower levels for IgG4 to CSP constructs was opposite to what was reported to occur after primary vaccination7 where a higher ratio between cytophilic (IgG1 and IgG3) to non-cytophilic (IgG2 and IgG4) CSP antibodies was associated with protection.