Treatment Information for Healthcare Professionals

Interim Clinical Guidance for the Treatment of Monkeypox

Many people infected with monkeypox virus have a mild, self-limiting disease course in the absence of specific therapy. However, the prognosis for monkeypox depends on multiple factors, such as previous vaccination status, initial health status, concurrent illnesses, and comorbidities among others. Patients who should be considered for treatment following consultation with CDC might include:

    • People with severe disease (e.g., hemorrhagic disease, confluent lesions, sepsis, encephalitis, or other conditions requiring hospitalization)
    • People who may be at high risk of severe disease:
      • People with immunocompromise (e.g., human immunodeficiency virus/acquired immune deficiency syndrome infection, leukemia, lymphoma, generalized malignancy, solid organ transplantation, therapy with alkylating agents, antimetabolites, radiation, tumor necrosis factor inhibitors, high-dose corticosteroids, being a recipient with hematopoietic stem cell transplant <24 months post-transplant or ≥24 months but with graft-versus-host disease or disease relapse, or having autoimmune disease with immunodeficiency as a clinical component)1
      • Pediatric populations, particularly patients younger than 8 years of age2
      • People with a history or presence of atopic dermatitis, persons with other active exfoliative skin conditions (e.g., eczema, burns, impetigo, varicella zoster virus infection, herpes simplex virus infection, severe acne, severe diaper dermatitis with extensive areas of denuded skin, psoriasis, or Darier disease [keratosis follicularis])
      • Pregnant or breastfeeding women3
      • People with one or more complications (e.g., secondary bacterial skin infection; gastroenteritis with severe nausea/vomiting, diarrhea, or dehydration; bronchopneumonia; concurrent disease or other comorbidities)4
    • People with monkeypox virus aberrant infections that include accidental implantation in eyes, mouth, or other anatomical areas where monkeypox virus infection might constitute a special hazard (e.g., the genitals or anus)

Medical Countermeasures Available for the Treatment of Monkeypox

Currently there is no treatment approved specifically for monkeypox virus infections. However, antivirals developed for use in patients with smallpox may prove beneficial against monkeypox. The following medical countermeasures are currently available from the Strategic National Stockpile (SNS) as options for the treatment of monkeypox:

Tecovirimat (also known as TPOXX, ST-246)

TPOXX is an antiviral medication that is approved by the United States Food and Drug Administration (FDA) [PDF – 24 pages] for the treatment of smallpox in adults and children. Data are not available on the effectiveness of tecovirimat in treating monkeypox infections in people, but studies using a variety of animal species have shown that tecovirimat is effective in treating disease caused by orthopoxviruses. Clinical trials in people showed the drug was safe and had only minor side effects. CDC holds an expanded access protocol (sometimes called “compassionate use”) that allows for the use of stockpiled tecovirimat to treat monkeypox during an outbreak. Tecovirimat is available as a pill or an injection. For children who weigh less than 28.6 pounds, the capsule can be opened, and medicine mixed with semi-solid food.

Vaccinia Immune Globulin Intravenous (VIGIV)

VIGIV is licensed by FDA [PDF – 18 pages] for the treatment of complications due to vaccinia vaccination including eczema vaccinatum, progressive vaccinia, severe generalized vaccinia, vaccinia infections in individuals who have skin conditions, and aberrant infections induced by vaccinia virus (except in cases of isolated keratitis). CDC holds an expanded access protocol that allows the use of VIGIV for the treatment of orthopoxviruses (including monkeypox) in an outbreak.

Data are not available on the effectiveness of VIG in treatment of monkeypox virus infection. Use of VIG has no proven benefit in the treatment of monkeypox and it is unknown whether a person with severe monkeypox infection will benefit from treatment with VIG. However, healthcare providers may consider its use in severe cases.

VIG can be considered for prophylactic use in an exposed person with severe immunodeficiency in T-cell function for which smallpox vaccination following exposure to monkeypox virus is contraindicated.

Cidofovir (also known as Vistide)

Cidofovir is an antiviral medication that is approved by the FDA [PDF – 6 pages] for the treatment of cytomegalovirus (CMV) retinitis in patients with Acquired Immunodeficiency Syndrome (AIDS). Data is not available on the effectiveness of Cidofovir in treating human cases of monkeypox.  However, it has shown to be effective against orthopoxviruses in in vitro and animal studies. CDC holds an expanded access protocol that allows for the use of stockpiled Cidofovir for the treatment of orthopoxviruses (including monkeypox) in an outbreak. It is unknown whether or not a person with severe monkeypox infection will benefit from treatment with Cidofovir, although its use may be considered in such instances. Brincidofovir may have an improved safety profile over Cidofovir.  Serious renal toxicity or other adverse events have not been observed during treatment of cytomegalovirus infections with Brincidofovir as compared to treatment using Cidofovir.

Brincidofovir (also known as CMX001 or Tembexa)

Brincidofovir is an antiviral medication that was approved by the FDA [PDF – 21 pages] on June 4, 2021 for the treatment of human smallpox disease in adult and pediatric patients, including neonates. Data is not available on the effectiveness of Brincidofovir in treating cases of monkeypox in people.  However, it has shown to be effective against orthopoxviruses in in vitro and animal studies. CDC is currently developing an EA-IND to help facilitate use of Brincidofovir as a treatment for monkeypox. However, Brincidofovir is not currently available from the SNS.

State and territorial health authorities can direct their requests for medical countermeasures for the treatment of monkeypox to the CDC Emergency Operations Center (770-488-7100).

References

1Petersen BW, Harms TJ, Reynolds MG, Harrison LH. Use of Vaccinia Virus Smallpox Vaccine in Laboratory and Health Care Personnel at Risk for Occupational Exposure to Orthopoxviruses—Recommendations of the Advisory Committee on Immunization Practices (ACIP), 2015. MMWR Morb Mortal Wkly Rep 2016;65:257–262. DOI: http://dx.doi.org/10.15585/mmwr.mm6510a2

2Jezek Z, Szczeniowski M, Paluku KM, Mutombo M. Human monkeypox: clinical features of 282 patients. J Infect Dis. 1987 Aug;156(2):293-8. doi: 10.1093/infdis/156.2.293. PMID: 3036967.

3Cono J, Cragan JD, Jamieson DJ, Rasmussen SA. Prophylaxis and treatment of pregnant women for emerging infections and bioterrorism emergencies. Emerg Infect Dis. 2006 Nov;12(11):1631-7. doi: 10.3201/eid1211.060618. PMID: 17283610; PMCID: PMC3372351. Mbala PK, Huggins JW, Riu-Rovira T, Ahuka SM, Mulembakani P, Rimoin AW, Martin JW, Muyembe JT. Maternal and Fetal Outcomes Among Pregnant Women With Human Monkeypox Infection in the Democratic Republic of Congo. J Infect Dis. 2017 Oct 17;216(7):824-828. doi: 10.1093/infdis/jix260. PMID: 29029147.

4Ogoina D, Iroezindu M, James HI, Oladokun R, Yinka-Ogunleye A, Wakama P, Otike-Odibi B, Usman LM, Obazee E, Aruna O, Ihekweazu C. Clinical Course and Outcome of Human Monkeypox in Nigeria. Clin Infect Dis. 2020 Nov 5;71(8):e210-e214. doi: 10.1093/cid/ciaa143. PMID: 32052029.