Effect of iron deficiency on natural immunity to malaria and malaria vaccine responses in African children

Objectives: To examine how iron deficiency (ID) affects development of natural protection against malaria infections and how well malaria vaccines work in children. Methods: We measured levels of 2 malaria antibodies and iron status markers in Kenyan (n=964) and Ugandan (n=870) children. We also measured malaria vaccine responses in children vaccinated with RTSS,S’ (n=115) and ME-TRAP vaccines (n=91). Children were classified as iron deficient or not using low ferritin (as defined by WHO) and / or low transferrin saturation (TSAT). Results: Overall, we found that levels of the two malaria antibodies were lower in iron deficient (low ferritin) compared to non-deficient children. Using the low TSAT definition, only one malaria antibody was lower in the iron deficient children. There was no significant difference in the response of RTSS vaccine between the two groups of children. ME-TRAP vaccine response was higher in iron deficient children six months after vaccination. Conclusions: The lower malaria antibody levels observed in children with ID may decrease their protection and recovery from malaria. Further research is required to investigate the relationship between ID and vaccine responses in African children.