Measles outbreaks in Nepal: sustaining rapid response through equity-focused immunization and surveillance

Recent measles outbreaks in Nepal's Sarlahi and Baglung districts show persistent subnational immunity gaps despite national progress toward measles elimination. This letter supports Nepal's rapid and coordinated outbreak response, particularly in Sarlahi, where early clinical suspicion, laboratory confirmation within 72 hours, household investigation, active case search, vitamin A supplementation, and outbreak response immunization were promptly implemented. These actions demonstrate the value of functional surveillance, laboratory capacity, and multisectoral coordination. However, the outbreaks also reveal that administrative declarations of high or full immunization coverage may mask susceptibility among marginalized and mobile populations. Cases clustered among under-immunized children in poor Muslim, Dalit, and migrant-linked communities, highlighting measles as a sensitive tracer of inequity in immunization systems. Sustained elimination will require ward-level microplanning, active identification of zero-dose and under-vaccinated children, catch-up vaccination for older cohorts, strengthened risk communication, and engagement of trusted community and religious leaders. Nepal's recent response provides an encouraging model, but long-term success depends on converting rapid outbreak control into preventive, equity-focused routine immunization.