A record-breaking measles outbreak in the US has ended. It may have helped drive vaccination rates

Key Points:

• South Carolina's measles outbreak, the largest in the US in decades with nearly 1,000 cases and 21 hospitalizations, has officially ended after no new cases were reported for over 42 days, marking two full incubation periods without transmission.
• The outbreak, which began in October, highlighted a national trend of rising measles cases linked to declining MMR vaccination rates, with over 90% of cases occurring in unvaccinated individuals, mostly children.
• Increased vaccination efforts in South Carolina, including a 31% statewide rise in MMR doses administered and aggressive public health measures, were critical in controlling the outbreak, costing the state around $2 million.
• Early data suggests a possible national uptick in MMR vaccination rates among young children, with CDC surveys indicating a rise to 97% coverage for 3-year-olds in 2025, potentially reflecting growing parental concern amid recent outbreaks.
• Despite these hopeful signs, experts warn that measles remains a significant threat in the US, with ongoing outbreaks and nearly 1,800 cases reported in 2026, emphasizing the need for continued vaccination efforts and public health vigilance.