Vitamin A administered with measles vaccine to nine-month-old infants doesnot reduce vaccine immunogenicity

After a report of reduced seroconversion to measles in infants, aged 6 mo, given vitamin A with their measles vaccination, serious concerns were raise d regarding the safety of the WHO's recommendation that infants be suppleme nted with vitamin A at the time of measles immunization. To determine the i mpact of coadministered vitamin A on the antibody response to measles vacci ne given to infants aged 9 mo, the more common age for immunization in deve loping countries, we conducted a randomized, double-blind, placebo-controll ed trial in an urban slum community in Delhi. Infants (618) were randomly a llocated to receive 30 mg vitamin A or a placebo with the measles immunizat ion. Antibodies to measles were measured by ELISA in serum samples obtained at before (baseline) and 12 wk after immunization. Overall, the seroconver sion rates did not differ between vitamin A (89.5%) and placebo (87.6%) gro ups. There were no significant differences in the geometric mean titers in the two groups (ratio of geometric means, 1.19; 95% confidence interval, 0. 97-1.46). Among malnourished infants, the geometric mean titer was signific antly greater in the vitamin A group compared to the placebo group (ratio o f geometric means, 1.57; 95% confidence interval, 1.18-2.0), but seroconver sion rates did not differ. There were no differences in seroconversion rate s and geometric mean titers in the two study groups among the well-nourishe d children. These results indicate that 30 mg vitamin A does not reduce the immune response to the coadministered vaccine and, therefore, can be conti nued to be given safely in public health programs.