Lessons Learned from Long-Term Assessment of Rotavirus Vaccination in a High-Income Country: The Case of the Rotavirus Vaccine Belgium Impact Study (RotaBIS)

Abstract

Introduction: The rotavirus (RV) vaccine Belgium Impact Study (RotaBIS) evaluated the vaccine effect on RV-related hospital care in children up to 5 years old over a period of 13 years. Different forces were identified that influence the reduction in hospital care. Our analysis aims to report on the current RotaBIS dataset and explore through model simulation whether, how, and when the results could have been improved. Methods: As performed in previous assessments, this analysis evaluated RV-related events per year, per age group, RV nosocomial infections, hospitalization duration, and herd effect.

Defining the Recipe for an Optimal Rotavirus Vaccine Introduction in a High-Income Country in Europe

“…Table 4 shows the observed data from RotaBIS by year and age group. The two models developed needed to be fitted to replicate these data as closely as possible [19].…”

“…Older children in the at-risk population can also spread the virus and act as secondary infection sources. In the prevaccination period, the importance of this secondary infection source is limited due to the dominance of the younger age group [19].…”

“…The seasonality of rotavirus disease requires the selection of a starting point for the vaccine programme that can reach high accumulated vaccine coverage before the next disease peak season by maximising vaccine administration to all infants born from the start of the vaccination to the first disease peak season. High vaccine coverage in the peak season is crucial, because this is the time of highest virus transmission within the at-risk group, and this should be reduced by the vaccination [19].…”

“…A key variable was the peak hospitalisation number reached in the post-uptake peaks. We analysed the observed data of the RotaBIS study by week during the post-uptake period to define this peak value, which was around 50 hospitalisations per week in the at-risk population (Figure 3) [19]. A H-S model assumes constant replenishment of susceptible individuals via newborns.…”

“…Universal mass vaccination (UMV) campaigns in HICs were initiated in the United States of America (U.S.), Belgium, and Austria in 2006, but the results of those programmes differed from the predicted modelling results after a few years of vaccine implementation [15][16][17]. To explain the causes of the discrepancies between the real-world data on rotavirus vaccination compared with the early model predictions, we constructed a mathematical model for the early years after vaccine introduction including variables that could affect the outcome [18], based on observed data from the country with the longest detailed observations of rotavirus vaccination impact over time (the RotaBIS study in Belgium) [19]. In the analysis presented here we have extended this research by developing a second mathematical model covering later years.…”