Will measles cases in the U.S. reach 1,900 by April 30, 2026? Current odds: 1%. Track the latest outbreak trends and vaccination rates in this live market.
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Measles is a highly contagious viral infection that the United States has largely controlled through childhood vaccination programs since the 1990s. The CDC maintains real-time surveillance of measles cases nationwide, making this market directly resolvable against official health data by April 30, 2026. At 1% implied probability, the market prices an outbreak of 1,900 cases as extraordinarily unlikely within the remaining window—a threshold that would require a rapid cascade of outbreaks across multiple states. The baseline U.S. measles incidence is typically in the dozens to low hundreds annually; reaching 1,900 cases would represent a significant public health event comparable to 2019's outbreak. Current price action reflects trader confidence that vaccination coverage and surveillance systems will prevent such a spike, though pockets of lower immunization in specific communities remain a latent risk factor. The odds have compressed downward as the resolution date approaches, since accumulating so many cases in just three days is statistically remote.
Measles eradication in the United States is considered one of public health's greatest achievements. Between 2000 and 2018, annual U.S. measles cases averaged fewer than 100, dropping to a low of 37 cases in 2004. This success stems from two primary factors: high childhood vaccination rates typically ranging from 90–95% nationally, and rapid outbreak response protocols. The measles-mumps-rubella (MMR) vaccine is highly effective, with documented coverage exceeding 92% in most states. However, measles has never been completely eliminated globally, and occasional importation occurs when international travelers or members of under-vaccinated communities bring the virus to the U.S., sparking localized clusters. The 2019 outbreak stands as the era's largest U.S. measles event, with 1,282 confirmed cases across 31 states—many concentrated in New York City among Orthodox Jewish communities experiencing vaccine hesitancy. This outbreak was contained through aggressive public health response: case isolation, contact tracing, vaccination clinics, and regulatory enforcement. Even during that severe year, reaching 1,900 cases would have required a 50% escalation from actual outcomes. The CDC's surveillance infrastructure is designed to detect and respond to clusters within days. For this market to resolve YES, the U.S. would need measles outbreak activity of unprecedented speed and scale within three days. This would require either a massive sudden importation event followed by explosive transmission in a largely unvaccinated population, or a cascade of surveillance failures across multiple states. Yet even if importation occurred immediately, containment measures—school closures, quarantine protocols, emergency vaccination campaigns—would likely suppress case accumulation below the threshold. No historical precedent exists for 1,900 U.S. measles cases in a 72-hour window given current vaccination coverage. The 1% odds reflect trader assessment that measles transmission remains slow relative to the resolution threshold. Traders have incorporated current low case counts (typically single digits to low dozens monthly), robust seasonal patterns, vaccine supply stability, and intact health infrastructure. No credible reporting suggests sudden vaccine hesitancy increases, surveillance degradation, or novel high-transmission variants. The market prices measles control as durable, assigning the small remaining probability only to black-swan scenarios.
The market resolves YES if the CDC reports at least 1,900 measles cases in the United States by April 30, 2026. Resolution uses official CDC surveillance data as the authoritative source.
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