Vitamin a supplementation does not affect infants' immune responses to polio and tetanus vaccines.
Newton S., Cousens S., Owusu-Agyei S., Filteau S., Stanley C., Linsell L., Kirkwood B.
It has been suggested that administering vitamin A with the measles vaccine may reduce the vaccine's immunogenicity. This trial examined the effect of supplementing vitamin A during the early months of life on infants' immune responses to tetanus and polio vaccines. Young infants (n = 1085) were enrolled and individually randomized into 1 of 4 groups in a factorial, double-blind, placebo-controlled trial. Three vitamin A supplementation strategies were investigated: 1) supplementation of breast-feeding mothers with 60 mg retinol equivalent (RE) vitamin A within 4 wk of delivery; 2) Expanded Program on Immunization (EPI)-linked supplementation of infants with 7.5 mg RE vitamin A at 6, 10, and 14 wk; and 3) combined mother and child supplementations. A 4th group in which mother and child were given placebos served as controls. Blood samples were collected from each child at 6 wk and 6 mo of age to measure antipolio antibody titer, antitetanus toxoid antibodies, and avidity of antibodies to tetanus. Of the infants randomized into the 4 arms of the study, 767 (71%) completed follow-up at 6 mo of age. Follow-up rates were similar in all 4 arms (69-72%, P = 0.8). Antibody titers were relatively high in all 4 groups at both 6 wk and 6 mo of age, with no differences among the groups. We found no evidence that vitamin A supplementation affects infants' antibody responses to tetanus toxoid or oral polio vaccine delivered at EPI contacts.