Understanding the role of exogenous boosting in modeling varicella vaccination.

This review identified an additional 41 studies: 22 observational and 19 modeling studies. Observational analyses generally reported pre-UVV increases in HZ incidence, making it difficult to attribute post-UVV increases to UVV versus other causes. Modeling studies considered a range of EB frameworks, from no boosting to full permanent immunity. Mathematical modeling efforts are needed in countries with long-standing vaccination programs to capture the dynamics of VZV transmission and temporal changes that may affect HZ incidence. Use of real-world pre-/postvaccination data on varicella and HZ incidence to validate model predictions may improve approaches to EB parameterization and understanding of the effects of varicella vaccination programs.