Conflict of interest: None declared. “
“Rotavirus is the leading cause of fatal and severe diarrhea in children [1]. In India, it is responsible for almost 100,000 deaths annually [2]. The WHO has recommended inclusion of rotavirus vaccines in all national immunization programs. Currently there are two licensed rotavirus vaccines available; Rotarix®, GSK Biologicals and RotaTeq®, Merck & Co. Both vaccines have demonstrated high efficacy (>90%) against severe rotavirus diseases and rotavirus associated hospitalization
in clinical trials in high- and middle-income countries [3], [4] and [5]. However, trials of these two vaccines conducted in developing settings in Africa and Asia showed lower efficacy, of approximately 60% [6], [7], [8] and [9]. Most recently, the indigenously manufactured live,
oral 116E monovalent human–bovine vaccine has completed an efficacy trial and is expected to be licensed learn more in India soon. The efficacy Selleckchem Epigenetics Compound Library of the 116E vaccine was 54% [10] which is similar to that of Rotateq® and Rotarix® in these settings. Other live oral vaccines have also performed poorly in low-income countries as compared to more affluent countries [11]. Current evidence indicates that decreased vaccine performance could be attributed to several factors including child or maternal malnutrition, environmental enteropathy, interference from maternal antibodies and presence of other intestinal infections [11]. Presence of rotavirus antibodies in breast milk and transplacental maternal antibodies is associated with impaired responses to rotavirus vaccines [12], [13] and [14]. Indian women seem to have higher concentrations of rotavirus neutralizing antibodies in breast milk than women in industrialized countries [15]. In vitro studies of the neutralizing effect of breast milk have suggested that withholding of breastfeeding around the time of rotavirus vaccine administration could improve the immune response to the vaccine [15]. Previous trials of rotavirus vaccines had not shown any difference
in the immune response to vaccine regardless of whether breast milk was given or not at the time of vaccine administration. In those trials information else on breastfeeding was available, however, breastfeeding was self-reported by mothers and the duration between breastfeeding and vaccination was not adequately assessed [16] and [17]. A recent study from South Africa reported that abstention from breastfeeding an hour before and after each vaccination had no substantial effect on the immune response to a rotavirus vaccine in HIV-uninfected infants [18]. Without clear evidence, it is difficult to determine whether rotavirus antibodies in breast milk interfere with immune response to oral rotavirus vaccines in infants. It is important to explore this association, as it may help improve the impact of the vaccines.