The_gut_microbiota_and_rotavirus_vaccine_efficacy

Rotavirus live oral vaccines have shown poor efficacy in developing world populations. In Malawi RV1 has recently been introduced with the expectation that it will have a major impact on child morbidity and mortality due to diarrhoea, however, vaccine trials showed an efficacy of 49%, in comparison to the >90% efficacy typically seen in high income countries. The natural history of rotavirus infections in an Indian slum birth cohort recently highlighted that rotavirus infections occur earlier in life , reinfections are very frequent in early in life, and that the number of infections required in order to confer subsequent protection from infection and disease is significantly greater than previously described in a cohort of children from Mexico. We want to explore the role of the gut microbiota composition on rotavirus vaccine failure  and our hypotheses are :i)  the gut microbiota at the time of vaccination will impact on vaccine take and immune response. ii) Upon rotavirus infection, development of disease and disease severity is affected by the gut microbiota. This project aims to generate pilot data in order to test these hypotheses in two cohorts, one from Malawi and the second from Vellore. This is justified because despite the rotavirus vaccine efficacy and disease burden being similar in the two populations, it is expected that there will be marked differences in the microbiota composition of the two populations.