Monkeypox (recently renamed Mpox) is a zoonotic illness caused by the monkeypox virus, an Orthopoxvirus in the same genus as the variola, vaccinia, and cowpox viruses. In May 2022 a Monkeypox outbreak was first identified in Europe leading to the largest outbreak outside of the African cradle leading to more than 80,000 cases and 97 deaths. The 2022 outbreak has been primarily associated with close intimate contact (including sexual activity) and most cases have been diagnosed among men who have sex with men, who often present with novel epidemiological and clinical characteristics. This emergence highlights multiple gaps of knowledge on Mpox and at a larger scale on Orthopoxvirus genus. The seminar will focus on the description of Mpox clinical and epidemiological features in a first part, and in a second part on novel data on virological and genomic features of the virus. It will present eventually preliminary data on of virus transmission from animal model in non-human primates.