In a randomized controlled trial follow-up study of Kenyan infants (n = 155), antimeasles serum IgG concentrations, seroconversion, and IgG avidity in the control and iron groups. The iron group received 5 mg iron daily for 4 months at time of measles vaccination. (A) Anti-measles serum IgG concentrations at age 7.5 and 11.5 months (at baseline and end of intervention), (B) seroconversion at age 11.5 months (at end of intervention), and (C) IgG avidity at age 11.5 months (at end of intervention). Data analyzed with random intercept linear mixed effect models with Bonferroni corrected multiple comparisons. Adapted from Stoffel et al.⁶