Mpox
An orthopoxvirus infection spread mainly through close skin-to-skin, intimate, respiratory, or contaminated-material contact.
What causes Mpox?
Mpox is caused by monkeypox virus. Transmission occurs through direct contact with lesions or body fluids, close intimate contact, contaminated materials, respiratory secretions during prolonged face-to-face contact, or from infected animals.
Symptoms and what to notice
A rash that may be painful or itchy, fever, chills, swollen lymph nodes, exhaustion, headache, muscle aches, sore throat, or respiratory symptoms. Lesions may be few and limited to genital, anal, oral, or other areas.
How long can it last?
Symptoms usually begin within 3 to 17 days after exposure. Illness often lasts 2 to 4 weeks and remains contagious until every lesion has healed, scabs have fallen off, and fresh skin has formed.
How serious is Mpox?
Most people recover, but severe pain, bacterial infection, eye involvement, pneumonia, encephalitis, dehydration, or disseminated disease can occur. Immunocompromised people, young children, and pregnant people may face higher risk.
Treatment and management
Many cases need pain control, wound care, hydration, and prevention of secondary infection. Tecovirimat may be available for people with severe disease or high risk under current access protocols; other medical countermeasures require specialist or public-health consultation.
Vaccine: who and when?
JYNNEOS is the primary U.S. mpox vaccine and is given as two doses 28 days apart to eligible people and as post-exposure prophylaxis. ACAM2000 is also approved for mpox and smallpox but has more contraindications and adverse-effect risks and is not the main outbreak vaccine.
Cost note: Patient cost varies by product, provider, insurance, location, and eligibility. Many recommended vaccines are covered in network without cost sharing, and qualifying children may use the Vaccines for Children program.
Trusted source
Patient cost varies by insurance, provider, location, and eligibility. Coverage and public-health access differ, so listed prices are examples rather than guaranteed patient prices. This page is for general education and does not replace individualized medical advice, diagnosis, vaccination assessment, or treatment.
Mpox: Symptoms, Causes, Treatment, Prevention, and Vaccine Information
Mpox is an orthopoxvirus disease whose presentation changed during the global clade II outbreak that began in 2022. Some patients have widespread lesions and fever, while others have only a few painful genital, anal, or oral lesions. A person may transmit virus before every symptom is recognized, and close physical or intimate contact is the dominant route in recent U.S. outbreaks.
Important: This page is for general education. It does not replace diagnosis, treatment, vaccination advice, or emergency care from a qualified healthcare professional.
Quick Facts
| Topic | Current information |
|---|---|
| Cause | Mpox is caused by monkeypox virus. Transmission occurs through direct contact with lesions or body fluids, close intimate contact, contaminated materials, respiratory secretions during prolonged face-to-face contact, or from infected animals. |
| Main symptoms | A rash that may be painful or itchy, fever, chills, swollen lymph nodes, exhaustion, headache, muscle aches, sore throat, or respiratory symptoms. Lesions may be few and limited to genital, anal, oral, or other areas. |
| Typical course | Symptoms usually begin within 3 to 17 days after exposure. Illness often lasts 2 to 4 weeks and remains contagious until every lesion has healed, scabs have fallen off, and fresh skin has formed. |
| Treatment | Many cases need pain control, wound care, hydration, and prevention of secondary infection. Tecovirimat may be available for people with severe disease or high risk under current access protocols; other medical countermeasures require specialist or public-health consultation. |
| Vaccine status | JYNNEOS is the primary U.S. mpox vaccine and is given as two doses 28 days apart to eligible people and as post-exposure prophylaxis. ACAM2000 is also approved for mpox and smallpox but has more contraindications and adverse-effect risks and is not the main outbreak vaccine. |
History and Public-Health Importance
Monkeypox virus was identified in laboratory monkeys in 1958 and the first recognized human case occurred in 1970. Historically, most cases were associated with parts of central and western Africa or animal exposure. The 2022 global outbreak demonstrated sustained person-to-person transmission outside historically affected regions. U.S. prevention now combines testing, isolation guidance, risk-based JYNNEOS vaccination, contact notification, and treatment access for severe disease.
What Causes Mpox?
Mpox is caused by monkeypox virus. Transmission occurs through direct contact with lesions or body fluids, close intimate contact, contaminated materials, respiratory secretions during prolonged face-to-face contact, or from infected animals.
Virus enters through broken skin, mucous membranes, or the respiratory tract. Direct contact with rash, scabs, or body fluids is efficient, including during sex. Clothing, bedding, towels, or sex toys can carry infectious material. Infection during pregnancy can affect the fetus. People should avoid close contact with animals because human-to-animal transmission can occur.
Symptoms and Typical Course
A rash that may be painful or itchy, fever, chills, swollen lymph nodes, exhaustion, headache, muscle aches, sore throat, or respiratory symptoms. Lesions may be few and limited to genital, anal, oral, or other areas.
Lesions can progress from spots to firm bumps, vesicles, pustules, and scabs, but stages may overlap. Rectal pain, painful swallowing, genital swelling, or eye symptoms can dominate the illness. A person is considered contagious until all scabs separate and a new layer of intact skin forms. Immunocompromised patients can have prolonged or progressive disease.
Complications and Who Is at Higher Risk
Most people recover, but severe pain, bacterial infection, eye involvement, pneumonia, encephalitis, dehydration, or disseminated disease can occur. Immunocompromised people, young children, and pregnant people may face higher risk.
Severe rectal or genital pain may require hospitalization. Eye infection can threaten vision. Bacterial superinfection, dehydration, pneumonia, neurologic disease, myocarditis, and disseminated necrotic lesions are possible. Advanced or uncontrolled HIV and other major immune suppression substantially increase the risk of severe or fatal disease.
How It Is Diagnosed
Clinicians usually swab one or more lesions for orthopoxvirus or monkeypox-virus PCR. Vigorous sampling from the lesion surface is important; unroofing is generally unnecessary. Testing for other sexually transmitted infections and HIV is often appropriate. Public health may assist with specimen routing and treatment eligibility.
Treatment and Recovery
Many cases need pain control, wound care, hydration, and prevention of secondary infection. Tecovirimat may be available for people with severe disease or high risk under current access protocols; other medical countermeasures require specialist or public-health consultation.
Pain should be assessed directly and treated with local and systemic options. Tecovirimat access and eligibility have changed over time; clinicians should follow current CDC pathways rather than assume routine prescribing. Severe cases may need brincidofovir, cidofovir, vaccinia immune globulin, or combination therapy through expert consultation. Supportive care remains essential.
Vaccine Information
JYNNEOS is the primary U.S. mpox vaccine and is given as two doses 28 days apart to eligible people and as post-exposure prophylaxis. ACAM2000 is also approved for mpox and smallpox but has more contraindications and adverse-effect risks and is not the main outbreak vaccine.
JYNNEOS is a nonreplicating modified vaccinia vaccine. Two doses four weeks apart provide the best protection; delayed second doses should be given rather than restarting. Vaccination after exposure is most useful as soon as possible, ideally within four days, and may reduce severity if given within 4 to 14 days before symptoms. Routine boosters are not recommended for most people, but some orthopoxvirus laboratory workers follow occupational booster schedules.
Prevention
Avoid skin-to-skin contact with lesions, share no bedding or personal items, clean contaminated surfaces and laundry safely, reduce exposure in sexual networks during outbreaks, and use vaccination when eligible. People with mpox should follow isolation guidance and cover lesions when around others for essential reasons.
When to Seek Medical Care
Seek urgent care for eye pain or vision change, breathing difficulty, confusion, rapidly spreading lesions, severe uncontrolled pain, dehydration, pregnancy, or significant immune suppression. Call ahead so the facility can use appropriate infection-control measures.
Frequently Asked Questions
Is mpox only sexually transmitted?
No. Sexual contact is one important close-contact route, but lesions, body fluids, respiratory secretions, contaminated materials, and infected animals can also transmit virus.
How long is mpox contagious?
Until every lesion has healed, all scabs have fallen off, and a fresh layer of skin has formed.
What vaccine is normally used?
JYNNEOS is the primary U.S. vaccine and is given in two doses 28 days apart.
Does vaccination treat active mpox?
No. It prevents infection or reduces risk after exposure; clinical care is still needed for active illness.
Key Takeaway
Mpox is controlled through early testing, lesion and pain care, contact precautions, risk-based JYNNEOS vaccination, and rapid escalation for severe or immunocompromised patients.
Medical, treatment, and vaccine information was reviewed against official U.S. public-health guidance available through September 2026.