Revision History

A measles outbreak that began among unvaccinated students at Broomfield High School in Colorado has grown to at least 10 cases and spread to an Arvada sports bar, marking the latest front in a national measles resurgence that has already produced over 1,281 cases across 31 states in 2026. The outbreak underscores how gaps in vaccination coverage — even at schools that meet herd immunity thresholds — can create pathways for one of the most contagious diseases known to medicine to move from classrooms into the broader community.