Effect of transmission intensity and age on subclass antibody responses to Plasmodium falciparum pre-erythrocytic and blood-stage antigens

- IgG1 and IgG3 to P. falciparum are lower in unstable than stable transmission areas.
- Cytophilic:non-cytophilic antibody ratios are decreased in unstable transmission.
- IgG3:IgG1 ratios for blood-stage antigens are decreased in unstable transmission.
- Low IgG3:IgG1 and cytophilic:non-cytophilic ratios may contribute to malaria risk.