Pediatr Infect Dis J.2010 Oct;29(10):919-23.
Inhibitory effect of breast milk on infectivity of live oral rotavirus vaccines.
Moon SS, Wang Y, Shane AL, Nguyen T, Ray P, Dennehy P, Baek LJ, Parashar U, Glass RI, Jiang B.
Source
National Centers for Immunization and Respiratory Disease, Centers for Disease Control and Prevention, Atlanta, GA, USA.
Abstract
BACKGROUND:
Live oral rotavirus vaccines have been less immunogenic and efficacious among children in poor developing countries compared with middle income and industrialized countries for reasons that are not yet completely understood. We assessed whether the neutralizing activity of breast milk could lower the titer of vaccine virus and explain this difference in vitro.
METHODS:
Breast milk samples were collected from mothers who were breast-feeding infants 4 to 29 weeks of age (ie, vaccine eligible age) in India (N = 40), Vietnam (N = 77), South Korea (N = 34), and the United States (N = 51). We examined breast milk for rotavirus-specific IgA and neutralizing activity against 3 rotavirus vaccine strains-RV1, RV5 G1, and 116E using enzyme immunoassays. The inhibitory effect of breast milk on RV1 was further examined by a plaque reduction assay.
INTERPRETATION:
The lower immunogenicity and efficacy of rotavirus vaccines in poor developing countries could be explained, in part, by higher titers of IgA and neutralizing activity in breast milk consumed by their infants at the time of immunization that could effectively reduce the potency of the vaccine. Strategies to overcome this negative effect, such as delaying breast-feeding at the time of immunization, should be evaluated.