Mpox is the illness formerly known as monkeypox; the World Health Organization approved the shorter name in 2022 to reduce stigma. It is a viral illness spread by close contact, causes fever and a characteristic rash (incubation 5–21 days), and public-health responses include testing, isolation of cases and vaccination with smallpox/mpox vaccines (e.g., Jynneos/Imvanex) for high-risk contacts.