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Mpox (formerly known as Monkeypox) is a rare disease caused by infection with the monkeypox virus. While Mpox is related to smallpox, its symptoms are generally milder, and it is rarely fatal. It is less contagious than smallpox. Mpox is a viral zoonotic disease, meaning it can spread when humans come into contact with infected animals. It also spreads between people.

The disease was discovered in 1958 when two outbreaks of a pox-like disease spread among colonies of monkeys being kept for research. Despite its name, scientists do not know the origin of the disease, which has also been identified in African rodents. The first case of Mpox in humans was reported in 1970.

People with Mpox get a telltale rash that looks like pimples or blisters and may appear on the genitals, anus, hands, feet, chest, or mouth. The rash may be painful or itchy and will turn to scabs as it heals. Other symptoms include fever, chills, swollen lymph nodes, exhaustion, muscle aches, headaches, and respiratory symptoms such as sore throat, nasal congestion, or cough. Symptoms usually start within 3 weeks of exposure. Mpox can be spread from the time symptoms appear until the rash heals, all scabs have fallen off, and a fresh layer of skin has formed. The illness typically lasts 2-4 weeks.

Mpox spreads in several ways.

  • Close – often skin-to-skin - contact with an infected person. This includes direct contact with Mpox rash, scabs, or bodily fluids from a person with Mpox. Examples of close contact include sexual acts, hugging and kissing, and prolonged face-to-face exposure
  • Touching objects, fabrics (bedding, towels, clothing), or surfaces that have been used by a person with Mpox
  • Contact with respiratory secretions
Scientists are still investigating whether Mpox can be spread by a person with no symptoms.

There are no treatments specifically for Mpox. However, antiviral drugs and vaccines developed for smallpox can be used to prevent and treat it. Two vaccines ACAM2000 and JYNNEOS (also known as Imvamune and Imvanex) are currently licensed in the United States to prevent smallpox. JYNNEOS is the preferred vaccine and is given in two doses. Protection peaks 14 days after the second dose. ACAM2000 is a single-dose vaccine and protection peaks 4 weeks after vaccination. ACAM2000 presents a risk of greater side effects and should not be taken by people with weakened immune systems. Both vaccines are effective in protecting people against Mpox. The U.S. Centers for Disease Control and Prevention recommends a person get vaccinated within 4 days of exposure to prevent onset of the disease. If given between 4-14 days after exposure, vaccination may reduce disease symptoms. There is currently a worldwide shortage of Mpox vaccine.

On July 23, 2022, the World Health Organization declared Mpox a global health emergency due to its appearance in 70 counties and 16,000 reported infections around the globe. The declaration was intended to draw worldwide attention to the outbreaks and prompt a coordinated international public health response.
Monkeypox is a rare infectious disease first discovered in 1958 after outbreaks occurred in monkeys kept for research. It is a more benign version of smallpox that is endemic in parts of Central and West Africa. During this panel conversation, we will discuss what is monkeypox, how concerned we should be in the U.S. and around the world, and measures that state, national, and international organizations are taking to monitor and address this issue.

Faculty of Interest

  • Associate Professor of Epidemiology (Microbial Diseases); Associate (Adjunct) Professor of Law, Yale Law School; Affiliated Faculty, Program in Addiction Medicine; Co-Director, Global Health Justice Partnership; Affiliated Faculty, Yale Institute for Global Health

    Research Interests
    • Computer Simulation
    • Decision Making
    • Hepatitis C
    • HIV
    • Operations Research
    • Political Systems
    • Prisoners
    • Public Policy
    • Social Justice
    • Social Medicine
    • Tuberculosis
    • United States Food and Drug Administration
    • Causality
    • Drug Approval
    • Drug Users
    • Social Determinants of Health
  • Associate Professor of Epidemiology (Microbial Diseases); Affiliated Faculty, Yale Institute for Global Health

    Research Interests
    • Aedes
    • Arthropod Vectors
    • Chikungunya virus
    • Culex
    • Dengue Virus
    • Disease Outbreaks
    • Epidemiology
    • Genetics, Microbial
    • Molecular Sequence Data
    • RNA Viruses
    • West Nile virus
    • Directed Molecular Evolution
  • Sterling Professor of Immunobiology and Professor of Dermatology and of Molecular, Cellular, and Developmental Biology and of Epidemiology (Microbial Diseases); Investigator, Howard Hughes Medical Institute

    Research Interests
    • Arboviruses
    • Autophagy
    • DNA Viruses
    • Herpes Simplex
    • Immune System
    • Immunity, Cellular
    • Immunity, Innate
    • Influenza, Human
    • Molecular Biology
    • Pneumonia, Viral
    • Pregnancy Complications
    • Proviruses
    • RNA Viruses
    • Sexually Transmitted Diseases
    • Tumor Virus Infections
    • Encephalitis, Viral
    • Central Nervous System Viral Diseases
    • Inflammasomes