Effects of iron and prebiotic supplementation on pediatric vaccine response
BACKGROUND: Iron deficiency anemia may impair adaptive immunity and may thereby reduce response to vaccines; vaccines often underperform in low- and middle-income countries. Oral iron might beneficial, but oral iron given to infants may cause gut inflammation and diarrhea, which may reduce efficacy of oral vaccines; prebiotics can mitigate these adverse changes associated with iron, and, given with iron, could maintain response to oral vaccines. GAP: We are aware of no previous controlled intervention studies with iron and/or prebiotics in African infants that assessed effects on vaccine response. HYPOTHESIS: (1) Provision of oral iron at time of vaccination in ID/IDA infants will improve iron status and thereby improve efficacy of IM vaccines; (2) Provision of oral iron and prebiotics at time of vaccination will improve iron status and reduce dysbiosis and inflammation and improve efficacy of oral vaccines. METHODS: Breastfeeding infants in southern Kenya (n=576) will be enrolled in a randomized, double-blind trial with a 4-arm factorial design to assess the effects of daily oral iron, prebiotics or placebo on the immunogenicity of pediatric vaccines. All infants will receive daily multivitamin syrup during the trial. Primary outcomes are vaccine seroconversion and IgG titers at 24, 38 and 52 weeks of age. RESULTS: Pending IMPACT: This study could provide the mechanisms and evidence-base for updated and improved guidelines to control iron deficiency anemia in infancy safely using iron and prebiotics in order to optimize response to pediatric vaccines.