Effect of breastfeeding on immunogenicity of oral live-attenuated human rotavirus vaccine: a randomized trial in HIV-uninfected infants in Soweto, South Africa

Abstract

To investigate the effect of abstention from breastfeeding, for an hour before and after each vaccination, on the immune responses of infants to two doses of rotavirus vaccine. In Soweto, South Africa, mother-infant pairs who were uninfected with human immunodeficiency virus (HIV) were enrolled as they presented for the "6-week" immunizations of the infants. Each infant was randomly assigned to Group 1 - in which breastfeeding was deferred for at least 1 h before and after each dose of rotavirus vaccine - or Group 2 - in which unrestricted breastfeeding was encouraged. Enzyme-linked immunosorbent assays were used to evaluate the titres of rotavirus-specific IgA in samples of serum collected from each infant immediately before each vaccine dose and 1 month after the second dose. Among the infants, a fourfold or greater increase in titres of rotavirus-specific IgA following vaccination was considered indicative of seroconversion. The evaluable infants in Group 1 (n=98) were similar to those in Group 2 (n=106) in their baseline demographic characteristics and their pre-vaccination titres of anti-rotavirus IgA. After the second vaccine doses, geometric mean titres of anti-rotavirus IgA in the sera of Group-1 infants were similar to those in the sera of Group-2 infants (P=0.685) and the frequency of seroconversion in the Group-1 infants was similar to that in the Group-2 infants (P=0.485). Among HIV-uninfected South African infants, abstention from breastfeeding for at least 1 h before and after each vaccination dose had no significant effect on the infants' immune response to a rotavirus vaccine.