Ongoing Clade II Mpox Global Outbreak

What to know

  • There are two types of mpox, clade I and clade II. The ongoing global outbreak that started in 2022 is caused by clade II. A current outbreak in Central and Eastern Africa is caused by clade I mpox.
  • Clade II mpox is endemic to West Africa.
  • After a peak in cases in summer 2022, cases of clade II mpox outbreak had decreased by early 2023 and continue to be reported at low levels in many countries today.
  • Clade II mpox is considered less severe than clade I mpox, and more than 99% of people survive their infection.
mpox
  • There are two types of mpox, clade I and clade II. The ongoing global outbreak that started in 2022 is caused by clade II. A current outbreak in Central and Eastern Africa is caused by clade I mpox.
  • Clade II mpox is endemic to West Africa.
  • After a peak in cases in summer 2022, cases of clade II mpox outbreak had decreased by early 2023 and continue to be reported at low levels in many countries today.
  • Clade II mpox is considered less severe than clade I mpox, and more than 99% of people survive their infection.

Clade II mpox around the world

Prior to the 2022 global outbreak, clade II mpox was found in Western Africa, with occasional travel-related cases in other parts of the world.

Since the outbreak began, clade II mpox has been seen in many countries where mpox had not previously been reported. Clusters of cases continue in many of these same countries.

Improved surveillance because of the ongoing capacity-building during the outbreak means cases can be found quickly. In late summer 2024, there were outbreaks in South Africa and Cote d'Ivoire.

Since January 1, 2022, there have been a total of more than 102,000 clade II mpox cases worldwide, with more than 220 reported deaths. Overall, the number of cases worldwide have gone down steadily since the peak in 2022. So far in 2024, there have been nearly 9,000 cases of clade II mpox around the world (Source: WHO).

CDC continues to work with international partners, global health organizations, and ministries of health on mpox preparedness, surveillance, and testing.

Notes:Case data reported in humans to WHO since January 1, 2024, are provided for situational awareness and subject to change. Confirmed cases include those laboratory-confirmed as monkeypox virus and may include cases only confirmed as orthopoxvirus. For more information and additional limitations, see WHO-reported data at 2022-24 Mpox (Monkeypox) Outbreak: Global Trends (shinyapps.io).

Source: 2022-24 Mpox Outbreak: Global Trends. Geneva: World Health Organization, 2024. Available online: https://worldhealthorg.shinyapps.io/mpx_global/ (last cited: August 27, 2024)

Mpox in the United States

Here's what we know about clade II mpox in the United States:

  1. The number of illnesses reported recently is far below the peak of the outbreak in July and August 2022, when the national 7-day average was more than 450 cases a day (or more than 11,000 per month). U.S. case counts have remained consistent at about 250 or less a month since October 2023.
  2. In 2023, there were a total of about 1,700 cases reported. So far in 2024, about 2,300 cases have been reported.
  3. Clade II mpox is still mostly being spread through sexual and intimate contact, with gay, bisexual, and other men who have sex with men at the highest risk of getting mpox.
  4. A CDC study indicates that getting two doses of mpox vaccine works to prevent mpox. It's rare for people to get mpox after they've been fully vaccinated or recovered from a prior infection. Right now, getting more than two mpox vaccine doses (a "booster") isn't recommended.
  5. Tecovirimat (TPOXX) is an investigational antiviral drug used to treat mpox, especially people with severe mpox or who are likely to get severely ill. The safety and effectiveness of TPOXX are being evaluated through the STOMP clinical trial. If you know someone newly diagnosed with mpox, encourage them to join this trial to get access to TPOXX and help people in the future.
  6. Based on what we know, people who have already had mpox or have had both doses of mpox vaccine are likely to be protected against both clades of mpox. This includes clade I mpox, which is circulating in Central and Eastern Africa.

What you should do

If you're eligible for the mpox vaccine, get vaccinated!

You're eligible for mpox vaccine if you're a gay, bisexual, or other man who has sex with men, or if you're transgender, gender non-binary, or gender-diverse AND have other sexual risk factors. You're also eligible if you are traveling to a country with a clade I mpox outbreak and anticipate of the following activities during travel, regardless of gender identity or sexual orientation: sex with a new partner; sex at a commercial sex venue; sex in exchange for money, goods, or other trade; sex in association with a large public event.

Most new clade II mpox cases continue to be in people at higher risk for mpox who were not vaccinated with JYNNEOS.

Wondering about boosters? A CDC study indicates that people who have received both doses do not need booster doses at this time. The CDC is continuing to monitor how well vaccine is working and will update recommendations as we learn more.

There has been a small number of infections in people who have been vaccinated, but vaccination is likely to make the infection milder and reduce the risk of severe infection and death.

You should get two doses of JYNNEOS 4 weeks apart. Even if it's been longer than 4 weeks since the first vaccine dose, you should get the second dose as soon as possible. If you've already been diagnosed with mpox, you don't need the vaccine.

Keep Reading: Mpox Vaccination

Avoid skin-to-skin contact and sharing contaminated materials with people who may have mpox

During the past two years, sexual behavior and other changes by people at higher risk for mpox helped reduce the spread of mpox.

If you're at risk and haven't gotten both doses of the vaccine yet, consider getting vaccinated to protect yourself.

Whether or not you've been fully vaccinated, other ways to protect yourself include avoiding close contact with people who are sick with signs and symptoms of mpox, including those with skin or genital lesions. In some cases, symptoms may be mild. If you or a sexual partner has or recently had mpox symptoms, or you have a new or unexplained rash anywhere on their body, see a healthcare provider. People who have mpox symptoms should not have sex or other close contact with people while they are ill, and until their rash is completely healed, which means scabs have fallen off and a fresh layer of skin has formed.

Also, avoid contact with contaminated materials used by people who are sick (such as clothing, bedding, toothbrushes, sex toys, or materials used in healthcare settings).

What CDC is doing

  • Since 2022, CDC has increased our capacity to detect cases of mpox through existing surveillance systems, including wastewater testing.
  • CDC, public health, and commercial laboratories have increased testing capacity to find cases of mpox quickly.
  • CDC is working with state, tribal, local, territorial, and commercial partners to closely monitor for mpox cases so health officials can quickly respond.
  • CDC works with key partners in the United States to get the word out about vaccination and reducing mpox risk.
  • CDC prioritizes health equity and continues to work with partners in the LGBTQ+ community to support vaccine uptake among the communities disproportionately affected by mpox. You can see some of this work in social media videos with Dashaun Wesley in collaboration with CDC Foundation.
  • CDC supports state and local health departments to increase mpox vaccine accessibility, demand, and uptake.
  • CDC funds studies to better understand why people decide to get vaccinated against mpox or not. Partner organizations, including the National Coalition of STD Directors and National Coalition for Sexual Health, used this research to develop equity-centered and free communications materials and a communication toolkit.

Resources

For the public

For clinicians, public health partners, and laboratory staff