In the St. Louis region this week, a single confirmed measles case has drawn a wide circle of concern, touching a beloved ballpark and neighborhood restaurants alike — a quiet reminder that diseases once thought vanquished have a way of returning when collective vigilance fades. Health officials, marking this as Missouri's third measles case of the season, are urging residents to see the moment not as cause for panic, but as an invitation to reflect on the shared responsibility of community immunity. The MMR vaccine, safe and widely available, remains the clearest answer to a virus that travel