4) as a result of the slow accumulation of susceptible individuals in a partially immunized population. Once susceptibles build up to high enough levels, via the introduction of births, a larger epidemic known as the ‘post-honeymoon outbreak’ occurs (post-vaccination year 3 in Fig. 4) before disease incidence stabilises at long-term post-vaccination levels. Long-term reductions in rotavirus disease incidence predicted by our model more closely resemble selleck chemical the numbers seen in the third post-vaccination year than those in the second post-vaccination year. The ‘honeymoon period’ predicted for

rotavirus is relatively subtle and short-lived compared to ‘honeymoon periods’ for fully immunizing infections. This can be explained, in part, by the fact that individuals are susceptible to multiple rotavirus infections. Our model indicates vaccination will confer both direct and indirect benefits to the population. This prediction is consistent with observed post-vaccination reductions in disease incidence in

the United States, which were greater than expected on the basis of estimated vaccine coverage [6]. The decrease in symptomatic infections in vaccinated individuals most likely leads to indirect protection for those not immunized by reducing the chances of contacting an infectious individual. Our model predicts that the average age of reported cases will increase with vaccination as the decrease in prevalence of infection Selleck SB203580 in the population delays the time to primary (and subsequent) infections. This increase in the average age of infection could lead to a further decrease in reported cases beyond those predicted by the model if cases in older children are less severe compared with those in infants, and therefore less likely to seek medical attention [38]. The model predicts that a single

two or three dose course of rotavirus vaccine will not eliminate rotavirus disease completely if the effect of the vaccine is truly comparable to the protection provided by natural infections. Terminal deoxynucleotidyl transferase This is not surprising given that immunity against natural rotavirus infections is short-lived and that infants may experience natural infections before completing the full vaccine course. When considering alternative scenarios for the mechanism of vaccine protection, we demonstrated that irrespective of how the vaccine might confer protection, minimal differences in impact are expected between two or three dose vaccine schedules. This finding is important as it is consistent with the results of clinical trials which have shown that the two-dose Rotarix schedule and the three-dose RotaTeq schedule have similar efficacy profiles [32].