Measles is a highly contagious viral disease spread through respiratory droplets, with infection rates around 90% in unvaccinated populations. The CDC tracks measles cases nationally through surveillance systems capturing reports from healthcare providers, laboratories, and state health departments. The 2200-case threshold represents a major outbreak scale, well above typical annual U.S. case counts, where vaccination coverage historically keeps measles rare. With only three days until April 30, this market asks whether a significant measles surge is already underway or imminent. The current 1% YES odds reflect extremely low trader conviction, suggesting the consensus views a 2200-case spike in this timeframe as highly unlikely given baseline case counts and the rapid escalation required to reach that threshold.
Deep dive — what moves this market
Measles control in the United States has been remarkably successful since endemic transmission was declared eliminated in 2000. While occasional cases still occur through international travel and periodic clusters emerge in communities with lower vaccination coverage, overall caseload remains far below pre-vaccine era levels when hundreds of thousands contracted the disease annually. The 2200-case threshold would represent a dramatic reversal—consistent with a major outbreak in a large, significantly under-vaccinated population or multiple simultaneous clusters across regions. CDC data shows approximately 90-95% of the U.S. population is immune to measles through either MMR vaccination or prior infection, creating substantial herd immunity that naturally restrains disease spread. However, pockets of lower vaccination exist in specific communities due to religious exemptions, philosophical objections, or access barriers, which could theoretically seed larger outbreaks if the virus circulates in such areas. Recent global measles outbreaks trace to imported cases from travelers in lower-vaccination countries, followed by limited secondary transmission in high-immunity populations. The current 1% odds imply traders assess the probability of accumulating 2200 cases in 72 hours as negligible—a reasonable assessment given that reaching such a threshold would require either an already-active widespread outbreak with hundreds of documented cases (typically public knowledge) or explosive exponential spread from an undetected reservoir. Weekly CDC case reports and state health department announcements provide primary data points for resolution; any major outbreak would typically trigger public health alerts and media coverage.
What traders watch for
CDC weekly measles report (Wednesday release) showing confirmed case counts approaching final deadline
State health department outbreak announcements or emergency declarations signaling rapid measles transmission
Travel-related case importations or detected cases in low-vaccination communities indicating onward spread
Laboratory confirmation delays that could affect reported case totals through April 30 deadline
How does this market resolve?
Market resolves YES if CDC confirms at least 2200 cumulative measles cases in the United States by April 30, 2026 at 11:59 PM ET. Resolution is determined by official CDC case counts and state health department reports.
Prediction markets aggregate trader expectations into real-time probability estimates. On Polymarket Trade, every market question resolves YES or NO based on a specific event outcome; traders buy shares of the side they believe will resolve positively. Prices range 0¢ (certain no) to 100¢ (certain yes) and naturally reflect the crowd-implied probability of YES. This page summarizes the market state for readers arriving from search; for live trading (place orders, see order book depth, execute a trade) open the full interactive page linked above.
