Russian health authorities have reported no confirmed pneumonic plague cases from the October 2026 incident at the Irkutsk Anti-Plague Research Institute, describing the laboratory worker’s death instead as pneumonia of undetermined etiology. Extensive testing found no dangerous pathogens among nearly 200 identified contacts, all of whom have completed observation with no secondary cases detected. The World Health Organization has assessed the risk of wider transmission as moderate to low within the region and very low internationally, consistent with pneumonic plague’s requirement for sustained close respiratory contact and the effectiveness of quarantine and contact tracing. Traders assign a 96.1% probability to “No” because no epidemiologically linked case outside Russia has emerged in the initial containment window. A confirmed international case before the December 31, 2026 resolution deadline remains possible only if undetected exportation or delayed laboratory confirmation occurs despite current controls.