Key Points

• From January 1 to June 30, 2026, 267 cases of smallpox B (mpox) were reported, including 10 cases without laboratory confirmation (Figure 1). The number of cases reported in the second quarter of 2026 (April–June) was three times that of the first quarter (January–March).
• Among the cases for which the clade could be identified, 65% (89/137) belonged to clade Ib, compared with 35% (48/137) to clade IIb.
• The reported cases involved 236 males (88%) and 31 females (12%). With the exception of 2 cases in children (< 15 years old), all reported cases were adults with a median age of 34 years. More than one-third resided in Île-de-France (112/267, 42%); 22% resided in the Indian Ocean departments, including 14% in Mayotte (37/267) and 8% in Réunion (21/267); 7% of cases resided in the PACA region (20/267) and 7% in the Grand Est region (19/267).
• In terms of risk exposure, 32% of documented cases (84/259) reported contact with a case within the 3 weeks prior to the onset of their symptoms. Of the 62 men who reported contact with a case, 46 (74%) indicated that the contact was a sexual partner. Among cases for which travel history was available, 37% (93/252) had traveled abroad within the 3 weeks prior to the onset of their symptoms, primarily in Europe (including 17 in Spain, 5 in Belgium, and 5 in Germany) and in sub-Saharan Africa (including 43 in Madagascar and 3 in Côte d’Ivoire).
•  Among the 258 cases for which this information was available, 29 (11%) were hospitalized, primarily for the management of severe pain (n = 21 cases) and/or generalized rashes (n = 16 cases).
• Regarding vaccination status, when known, 76% of cases (166/218) had not received any vaccine doses since May 2022. Among the 52 vaccinated cases, 18 had received only one dose (including 4 with a history of vaccination prior to 1984), 25 had received two doses (including 2 with a history of vaccination before 1984), and 4 had received three doses. The number of doses received since 2022 was unknown for 5 cases.