Treatment

At this time, there are no specific treatments available for monkeypox infection, but monkeypox outbreaks can be controlled.

Smallpox vaccine, cidofovir, ST-246, and vaccinia immune globulin (VIG) can be used to control a monkeypox outbreak. CDC guidance was developed using the best available information about the benefits and risks of smallpox vaccination and drug use for the prevention and management of monkeypox and other orthopoxvirus infections.

Monkeypox and Smallpox Vaccine

One vaccine, JYNNEOSTM (also known as Imvamune or Imvanex), has been licensed in the United States to prevent monkeypox and smallpox. Because monkeypox virus is closely related to the virus that causes smallpox, smallpox vaccine can also protect people from getting monkeypox. Past data from Africa suggests that smallpox vaccine is at least 85% effective in preventing monkeypox. The effectiveness of JYNNEOSTM against monkeypox was concluded from a clinical study on the immunogenicity of JYNNEOS and efficacy data from animal studies. Experts also believe that vaccination after a monkeypox exposure may help prevent the disease or make it less severe.

Smallpox vaccines licensed in the United States include ACAM2000, which contains a live vaccinia virus, and JYNNEOSTM, a live non-replicating vaccine. The U.S. Food and Drug Administration (FDA) licensed ACAM2000® for immunization in people who are at least 18 years old and at high risk for smallpox or monkeypox infection. The Advisory Committee on Immunization Practices (ACIP) is currently evaluating JYNNEOSTM for the protection of people at risk of occupational exposure to orthopoxviruses in a pre-event setting.

Smallpox vaccine is not currently available to the general public. In the event of another outbreak of monkeypox in the U.S., CDC will establish guidelines explaining who should be vaccinated. For more information about the smallpox vaccine please visit CDC’s Smallpox Vaccination Information for Health Professionals.

Components of a smallpox vaccination kit including the diluent, a vial of Dryvax® smallpox vaccine, and a bifurcated needle.

Smallpox vaccination kit.

Cidofovir and Brincidofovir (CMX001)

Data is not available on the effectiveness of Cidofovir and Brincidofovir in treating human cases of monkeypox.  However, both have proven activity against poxviruses in in vitro and animal studies.

It is unknown whether or not a person with severe monkeypox infection will benefit from treatment with either antiviral, although their 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.

Tecovirimat (ST-246)

Data is not available on the effectiveness of ST-246 in treating human cases of monkeypox.

Studies using a variety of animal species have shown that ST-246 is effective in treating orthopoxvirus-induced disease. Human clinical trials indicated the drug was safe and tolerable with only minor side effects.

Although currently stockpiled by the Strategic National Stockpile, use of ST-246 is administered under an IND.

Vaccinia Immune Globulin (VIG)

Data is not available on the effectiveness of VIG in treatment of monkeypox complications. Use of VIG is administered under an IND and has no proven benefit in the treatment of smallpox complications. It is unknown whether a person with severe monkeypox infection will benefit from treatment with VIG, however, its use may be considered in such instances.

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 is contraindicated.

Related Links

CDC’s Smallpox Vaccine Information for the General Public