Monkey pox virus (MPXV), of the genus Orthopoxvirus, regularly causes epidemics in endemic areas of central and western Africa. Since January 1, 2022, cases of Monkey pox have been reported to WHO by 96 Member States in the 6 WHO regions. As of 22 August 2022, a total of 41,664 laboratory-confirmed cases and 192 probable cases, including 12 deaths, have been reported to WHO. Since May 13, 2022, a high proportion of these cases have been reported from countries where monkey pox transmission had not previously been documented. For the first time, cases and sustained chains of transmission are being reported in countries without direct or immediate epidemiological links to areas in West or Central Africa (WHO 2022). France is one of the most affected countries with 2889 cases reported as of August 22, 2022. This situation led the WHO Director General to declare, on July 23, 2022, that the monkeypox epidemic currently affecting several countries constitutes a Public Health Emergency of International Concern. To address this epidemic, the WHO has recommended Post Exposure Vaccination (PEP) and Pre Exposure Vaccination (PrEP) for at risk groups with 2nd and 3rd generation vaccines. In France, the Haute Autorité de Santé (French National Authority for Health) recommended on May 20, 2022, vaccination for PEP and on July 7, 2022, for PrEP with a 3rd generation MVA-BN vaccine (Imvanex® or Jynneos®). The European Medicines Agency (EMA) has approved the use of Imvanex® on July 22, 2022 for immunization against MPXV. The objective of the present study is to describe the clinical, biological, virological, pathophysiological and immunological aspects in the short and medium term of persons vaccinated against and infected with MPXV.