Effects of geographic and economic heterogeneity on rotavirus diarrhea burden and vaccination impact and cost-effectiveness in the Lao People's Democratic Republic.

Rotavirus enteritis is responsible for nearly 200,000 child deaths worldwide in 2015. Globally, many low- and middle-income countries have introduced rotavirus vaccine, resulting in documented reductions in hospitalizations and child mortality. We examined the potential impact and cost-effectiveness of introducing rotavirus vaccination in Lao People's Democratic Republic using an Excel-based spreadsheet model. We estimated mortality risk factors, patterns of care seeking, and vaccination access to predict outcomes for regional, provincial, and socioeconomic subpopulations for one birth cohort through their first five years of life and life course in Disability-Adjusted Life Years estimates. Socioeconomic status was defined by categorizing households into regional wealth quintiles based on a national asset index. We modeled a two-dose ROTARIX vaccine under current Gavi pricing and efficacy estimates from Bangladesh and Vietnam. DPT1 and DPT2 coverages were used to estimate rotavirus vaccination coverage. Probabilistic sensitivity analysis was used to assess the impact of uncertainty on model parameters on predicted incremental cost-effectiveness ratios (ICERs), including scenarios of increases in vaccination coverage. Rotavirus vaccination would prevent 143 child deaths/year, or 28% of annual rotavirus burden. The estimated national level ICER for rotavirus vaccination was $140/DALY, with regional socioeconomic subpopulation estimates ranging from $72/DALY for the poorest in the Central region to $353/DALY for the richest in the North region, indicating high cost-effectiveness. Within regions, ICERs are most favorable for children in the poorer and poorest quintiles. However, the full benefits of rotavirus vaccination will only be realized by reducing disparities in vaccination coverage, access to treatment, and environmental health. Improving vaccination coverage to equitable levels alone would prevent 87 additional child deaths per year.