US measles cases reach 35-year high, for second record-breaking year in a row

Key Points:

• The United States is experiencing a historic resurgence of measles in 2026, with more cases reported halfway through the year than any year since 1991, surpassing last year's record and marking a public health failure largely driven by unvaccinated children.
• South Carolina has been a major hotspot, with a large outbreak in Spartanburg County from October 2025 to April 2026 totaling nearly 1,000 cases, highlighting challenges in contact tracing and community spread despite high vaccination rates in some groups.
• Nationwide, more than 90% of measles cases are among unvaccinated individuals or those with unknown vaccination status, with 35 new outbreaks in 2026 and cases reported in all but seven states, putting the US measles elimination status at risk.
• Public health responses are labor-intensive, requiring extensive contact tracing and community coordination, as seen in Virginia and Pennsylvania, where local health departments are engaging communities through education, mobile clinics, and vaccination campaigns to contain outbreaks.
• Experts emphasize that maintaining vaccination rates above 95% is critical to preventing outbreaks, noting that pockets of low vaccination coverage continue to fuel the spread despite overall high coverage in some regions.