The Clinical Impact and Cost-effectiveness of Measles-Mumps-Rubella Vaccination to Prevent Measles Importations Among International Travelers From the United States.

Abstract

Measles importations and the subsequent spread from US travelers returning from abroad are responsible for most measles cases in the United States. Increasing measles-mumps-rubella (MMR) vaccination among departing US travelers could reduce the clinical impact and costs of measles in the United States. We designed a decision tree to evaluate MMR vaccination at a pretravel health encounter (PHE), compared with no encounter. We derived input parameters from Global TravEpiNet data and literature. We quantified Riskexposure to measles while traveling and the average number of US-acquired cases and contacts due to a measles importation. In sensitivity analyses, we examined the impact of destination-specific Riskexposure, including hot spots with active measles outbreaks; the percentage of previously-unvaccinated travelers; and the percentage of travelers returning to US communities with heterogeneous MMR coverage. The no-encounter strategy projected 22 imported and 66 US-acquired measles cases, costing $14.8M per 10M travelers. The PHE strategy projected 15 imported and 35 US-acquired cases at $190.3M per 10M travelers. PHE was not cost effective for all international travelers (incremental cost-effectiveness ratio [ICER] $4.6M/measles case averted), but offered better value (ICER <$100 000/measles case averted) or was even cost saving for travelers to hot spots, especially if travelers were previously unvaccinated or returning to US communities with heterogeneous MMR coverage. PHEs that improve MMR vaccination among US international travelers could reduce measles cases, but are costly. The best value is for travelers with a high likelihood of measles exposure, especially if the travelers are previously unvaccinated or will return to US communities with heterogeneous MMR coverage.