Key Points

• From January 1 to March 31, 2026, 67 cases of smallpox B (mpox) were reported, including 3 without laboratory confirmation.
• As of the date of this bulletin, clade Ib has become the predominant clade among indigenous and imported cases identified in France.
• Virus transmission predominantly affects men who have sex with men (MSM) in mainland France, whereas it is predominantly heterosexual in the Indian Ocean departments.
• Prevention measures, particularly preventive vaccination for eligible individuals (see below), remain relevant.