Mpox (formerly known as Monkeypox)
Mpox is a rare disease caused by the Mpox virus (MPV). Mpox (formerly known as Monkeypox) is not a new disease but was not common in the United States before the initial outbreak in the United States in 2022. In the late summer and fall of 2025, we have seen an increase in Mpox cases in Chicago.
Anyone can get Mpox. Mpox cases are more common in some populations than others. Vaccination is a very important way to prevent or decrease the severity of Mpox infections in groups where Mpox infection is more common. See the ‘vaccine eligibility’ section below to decide if you might be in a group which Mpox vaccination may be considered.
How It Is Transmitted
Mpox is spread from person to person through close contact, such as touching someone’s rash and sores, sharing bedding or towels, or respiratory droplets during prolonged face-to-face contact or intimate physical contact like kissing, cuddling, or sex.
Public health officials currently believe that MPV can be transmitted from person to person from the time symptoms start until the rash has fully healed. This typically takes about 2-4 weeks.
Signs & Symptoms
Symptoms typically start to appear anywhere between several days to 21 days after an exposure. If you have Mpox you may experience the following symptoms:
- Fever
- Headache
- Muscle aches
- Backache
- Swollen lymph nodes
- Chills
- Exhaustion
- Rash
- Sores, bumps and/or lesions on the skin
The rash will typically resemble pimples or blisters and eventually scabs over and heals. It can appear on the face, inside the mouth, genital area, area around the anus or on other parts of the body. The illness usually lasts 2-4 weeks.
Testing
If you are concerned about Mpox and have active lesions or rash, contact your primary care physician to be evaluated and see if you should get tested. Make sure your health care provider’s office knows you might have mpox before going to the clinic.
Treatments
Many people with Mpox will recover on their own without any additional treatment.
Certain individuals may qualify for an antiviral medication to treat MPV who are at risk of having more severe infections.
Vaccine
The vaccine requires 2 doses, with the second dose administered 28 days after the first. UI Health has the JYNNEOS™ vaccine available for UI Health patients and is following the Chicago Department of Public Health’s guidelines for administering it. If you are a UI Health patient and you believe that you should receive the Mpox vaccine based on the below recommendations, please contact your healthcare provider for additional information.
Vaccine Eligibility
At this time, MPV vaccination is not recommended for the general public. Eligibility for MPV vaccination may change over time. For the latest guidance, please visit CDPH's MPV vaccine resource site.
As of September 26, 2025, the following groups are currently eligible for vaccination (subject to change):
Group 1: Anyone, regardless of sex, gender, or sexual orientation, who:
- Had a known or suspected exposure to Mpox
- Had a sexual partner in the past 2 weeks diagnosed with Mpox
- Exchanged goods or services for sex in the last six months
- Had sex at a commercial sex venue (like a sex club or bathhouse)
- Had sex related to a large commercial event
Group 2: Gay, bisexual, and other same gender loving men, nonbinary, gender diverse or transgender individual who in the past six months have had:
- A new diagnosis of one or more nationally reportable sexually transmitted diseases (i.e., newly diagnosed HIV, chancroid, chlamydia, gonorrhea, or syphilis)
- More than one sexual partner
Group 3:
- Sexual partners of people from the above Groups 1 and 2
- People who anticipate experiencing the situations in Group 1
If you have had Mpox recently, you likely have protection and are not eligible to be vaccinated at this time.
Even after getting vaccinated, you should still take precautions, especially if you are at high risk for severe illness from Mpox.
