As of April 2, 2026, the CDC reports 1,671 confirmed measles cases across 33 U.S. jurisdictions, with 94% outbreak-associated amid 17 new outbreaks this year, primarily fueled by global surges importing the virus into under-vaccinated communities. Over 92% of cases occur in unvaccinated individuals or those with unknown status, reflecting pockets of vaccination coverage below the 95% herd immunity threshold needed to curb this highly contagious paramyxovirus (R0 of 12–18). Major clusters persist in states like South Carolina, Utah, and Texas, where transmission continues despite public health interventions. Traders should monitor weekly CDC surveillance updates and MMWR reports for case trajectories, as intensified vaccination drives or containment successes could slow accumulation toward year-end totals, while unchecked spread risks exceeding 2025's 2,279 cases.