Since January, our emergency team has been responding to a measles outbreak along the Turkana–Tiaty border. This follows an exploratory assessment in January by MSF emergency teams in Tiaty East, confirming an ongoing outbreak with transmission patterns that remain partly unclear due to weak surveillance, low routine immunization coverage, and severe access challenges in remote communities. The team identified four key hotspots with active or recent transmission, particularly in hard-to-reach areas along the Tiaty borders with Turkana and Samburu. In response to it, to support the local health authorities, MSF in collaboration with the Baringo County department of health launched a comprehensive response focused on active case finding, case management (through roving teams and outreaches), health promotion, community engagement, and currently mass vaccination for children under five years. This outbreak happens after a recent mass vaccination campaign in the area reported in July 2025, with a 95% coverage reported and a recent targeted measles campaign this January by MoH and its partners(UNICEF)