Three Years On: Chicago's 2025 Mpox Response and Continuing Prevention Efforts

CHICAGO - As 2025 winds down, the Chicago Department of Public Health (CDPH) looks back at a year marked by unexpected challenges and hard-earned progress in the city's mpox response. More than three years from the ongoing nationwide clade II mpox outbreak that began in 2022, the virus continues to circulate at low levels locally and globally, underscoring the ongoing need for awareness, vaccination, and vigilance.

Through the first six months of 2025, there were fewer than 20 new mpox cases in Chicago. By July though, the city was experiencing a mid-summer to early fall outbreak of clade II mpox that was met with an all-hands-on-deck response from CDPH. Between June and November, CDPH rapidly scaled up disease investigation, clinical outreach, vaccination, and community engagement efforts, working closely with healthcare providers and LGBTQ+ community partners across the city. These coordinated actions successfully contained the outbreak by early November, with new cases declining to fewer than one per day for several consecutive weeks.

In December, CDPH identified Chicago's first case of clade I mpox. This diagnosis was recognized by an astute clinician based on history of exposure to a traveler from an area with ongoing mpox clade I transmission and Clade I MPXV testing was confirmed with the support from the CDC. The individual had traveled internationally, sought care promptly and fully recovered. No associated transmission was identified.

While clade I mpox remains very rare in the U.S. and overall risk is low, mpox can result in serious illness and hospitalization, especially in people who are immunocompromised. This case highlights the importance of continued mpox surveillance and preparedness regardless of mpox clade.

Looking ahead to 2026, CDPH will continue to track mpox, support community partners and providers, and offer vaccination opportunities citywide. Vaccination remains the most effective tool to reduce mpox risk and protect against severe illness, hospitalization, and death. Chicagoans who may be at risk are encouraged to complete the two-dose mpox vaccine series, in addition to other indications for mpox vaccination, vaccination is recommended prior to travel to any country with a clade I mpox outbreak or community transmission for individuals who anticipate sexual or intimate contact while traveling, regardless of gender identity or sexual orientation.

Visit chicago.gov/mpox for up-to-date information on symptoms, testing, vaccination locations, and local data.

There are a few upcoming vaccination clinics on December 22, at the following locations:

• Center on Cottage Grove, 6323 S. Cottage Grove, 3-5 pm
• Life is Work, 600 N. Cicero Ave., 11 am-2 pm
• CALOR, 3201 W. North Ave., 4-7 pm
• CDPH also offers Mpox vaccinations at our Sexual Health Clinics:
  • Mondays, 9 am-12 noon: Roseland, 200 E. 115th St.
  • Tuesdays, 1-4 pm: Austin, 4909 W. Division St.
  • Fridays, 1-3:30 pm: Lakeview, 2849 N. Clark St.
• Mpox vaccinations are also available at CDPH Immunization Clinics.

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