Understanding variation in rotavirus vaccine efficacy and waning of vaccine-induced immunity

Rotavirus vaccines exhibited considerably lower efficacy during clinical trials conducted in developing countries compared to developed countries. We are using mathematical models to explore potential explanations for this reduced efficacy. Our analysis points towards factors that explain the reduced protection conferred by both vaccination and natural infection, such as malnutrition and concomitant infections with bacteria and helminthes, as the primary reason for the reduced vaccine efficacy in developing countries. We also are exploring potential explanations for the “waning” of vaccine efficacy observed in low socioeconomic settings.