San Francisco confirms first case of Clade 1 Mpox

On April 14, 2026, the San Francisco Department of Public Health confirmed the city's first case of Clade I mpox.

The patient, an unvaccinated adult, required hospitalization but is currently recovering.

Health officials note that the virus was transmitted via close contact with an international traveler.

While Clade I—which is linked to outbreaks in parts of Africa—is considered more severe than the Clade II variant seen in the 2022 US outbreak, the overall risk to the general public remains low.

Medical experts stress that the JYNNEOS vaccine is effective against both clades and strongly advise those at higher risk to complete their two-dose series.

Clinicians are also urged to remain alert for potential cases in patients with recent international travel history.