Assessing the cost-effectiveness of a Universal Rotavirus Vaccination program for the Philippines using a dynamic transmission model

Evaluate the cost-effectiveness of universal rotavirus vaccination of children below age of five years old in the Philippine setting We developed an age-stratified dynamic transmission model which compared four settings (baseline of no vaccine with 34% exclusive breastfeeding rate (EBR), two-dose monovalent vaccine (RV1), three-dose pentavalent vaccine (RV5), and no vaccine with 80% EBR) in the Philippine population over a 5-year time horizon. Model parameters such as cost and vital statistics were Philippine specific and other parameters such as vaccine efficacy and utility were extrapolated from literature. Univariate one-way and multivariate probabilities sensitivity analyses were conducted. Compared to baseline, the model showed that vaccination could lead to significant reduction in rotaviral morbidity and mortality in the 0 to <5 age group as well as inducing herd immunity in the older groups. The incremental cost-effectiveness ratios (ICER) of vaccination versus baseline from a societal perspective were US$ 13,184/DALY for RV1 and US$ 11,836/DALY for RV5; these are higher than the the current government cost-effectiveness threshold equal to the Philippine GNI per capita of US$ 3,134. Comparing 80% EBR to baseline, ICER is US$ 256,417/DALY. ICERs were sensitive to changes in case fatality, proportion of diarrhea cases due to rotavirus, and vaccine efficacy. The vaccine was cost-effective in less than 10% of 5000 Monte Carlo simulations. We estimated cost-effective prices of US$ 2.85/dose RV1 and US$ 1.96/dose RV5 which were lower than the current price of US$ 9.85/dose RV1 and US$ 6.43/dose RV5. Despite herd immunity benefits, universal vaccination using either RV1 or RV5 is unlikely to be cost-effective, at current tendered prices, for the Philippine setting, despite the herd immunity benefits. It might be due to comparatively low case-fatality rates. Current prices need to be decreased around 70% to achieve cost-effectiveness.