On August 4, 2022, the U.S. Centers for Disease Control and Prevention declared mpox a public health emergency in the United States.

Symptoms include a rash that forms blisters and then crusts over, fever, and swollen lymph nodes.

[9] Diagnosis can be confirmed by polymerase chain reaction (PCR) testing a lesion for the virus's DNA.

Some monitors saw community transmission taking place in the London area as of mid-May,[16] but it has been suggested that cases were already spreading in Europe in the previous months.

It is believed to be transmitted by close contact with sick people, with extra caution for those individuals with lesions on their skin or genitals, along with their bedding and clothing.

[18] In addition to more common symptoms, such as fever, headache, swollen lymph nodes, and rashes or lesions, some patients have also experienced proctitis, an inflammation of the rectum lining.

CDC has also warned clinicians to not rule out mpox in patients with sexually transmitted infections since there have been reports of co-infections with syphilis, gonorrhea, chlamydia, and herpes.

[19] The CDC has stated that, among mpox cases with available data, 99% occurred in men, 94% of whom reported recent male-to-male sexual or close intimate contact.

[34] On May 22, President Biden gave a speech at Osan Air Base in South Korea during which he indicated the disease was "something that everybody should be concerned about".

[44] In early June 2022, a man in Washington, D.C., was reported to test positive for orthopox, potentially mpox.

[102] The United States spent $119 million to purchase doses of the Modified vaccinia Ankara-based two-shot[103] Jynneos vaccine from Bavarian Nordic in May 2022.

[105] The vaccine, JYNNEOS (also known by the brand names Imvamune and Imvanex), was approved by FDA in 2019 to prevent both smallpox and mpox.

[19][106] In addition, the Strategic National Stockpile (SNS) holds over 100 million doses of an older smallpox vaccine (ACAM2000).

[107] As of June 28, the Biden administration was allocating tens of thousands of vaccine doses from the Strategic National Stockpile to clinics nation-wide.

The White House Pandemic Office had previously reinstated Dr. Beth Cameron to the executive position.

As of June 29, HHS has received requests from 32 states and jurisdictions, deploying over 9,000 doses of JYNNEOS vaccine and 300 courses of ST-246 (tecovirimat)[113][114] antiviral smallpox treatments.