Recent CDC surveillance data show the U.S. measles case total already exceeding 1,800 confirmed infections by mid-May 2026, driven primarily by large, ongoing outbreaks in multiple states among unvaccinated children and adolescents. With 92 percent of cases linked to individuals who are unvaccinated or whose status is unknown, transmission remains efficient in communities with coverage gaps below the 95 percent herd-immunity threshold. Official counts continue rising at a pace that places the cumulative total well above typical seasonal benchmarks, with weekly CDC updates and summer travel season expected to add further cases before the May 31 resolution window closes. Traders are therefore pricing near-certainty on higher thresholds, reflecting both the current trajectory and the limited time remaining for any meaningful slowdown in reported incidence.