The effectiveness of the measles and rubella immunization program in the Lao People's Democratic Republic was evaluated based on seropositivity of serum antibodies in two cross-sectional surveys. This is the first population-based study of measles and rubella in a developing country at two different time points. Serum antibody positivity rates for measles and rubella increased significantly from 2014 to 2019, well above the immunization threshold required to eliminate measles and rubella.

https://doi.org/10.1016/j.ijid.2023.01.044