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To date, published data on the circulation of MPXV clade\u2009IIb in the central African region are absent. Here we describe a case of laboratory-confirmed mpox clade\u2009IIb lineage A2.2 in Pointe-Noire, the second largest city of the Republic of the Congo. Whole-genome phylogenetic analysis placed the MPXV in clade\u2009IIb, lineage A.2.2 currently emerging in West Africa, in particular Sierra Leone. An additional 16 cases of clade\u2009Ia, 32 cases of clade\u2009Ib and one additional introduction of clade\u2009IIb were identified by passive surveillance in the Republic of the Congo in 2025. The detection of clade\u2009IIb mpox marks the third distinct MPXV clade and lineage co-circulating in the human population, together with clade\u2009Ia and Ib. This underscores the need for improved surveillance and diagnostic strategies to identify the respective clade and lineage circulating in the human population. Strengthening of regional capacity for case detection, contact-tracing, public health measures and affordable vaccines are urgently needed to reduce the global risk for both clade\u2009I and clade\u2009II MPXV.<\/jats:p>","DOI":"10.1038\/s41591-026-04256-2","type":"journal-article","created":{"date-parts":[[2026,4,3]],"date-time":"2026-04-03T09:04:00Z","timestamp":1775207040000},"page":"1666-1670","update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Evidence of monkeypox virus clade IIb lineage A.2.2 in the Republic of the Congo and co-circulation of clade Ia, Ib and clade IIb"],"prefix":"10.1038","volume":"32","author":[{"given":"Felix","family":"Koukouikila-Koussounda","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5195-5478","authenticated-orcid":false,"given":"Claude","family":"Kwe Yinda","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pembe","family":"Issamou Mayangue","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dachel","family":"Aymard Eyenet Boussam","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Reiche","family":"Golmard Elenga","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Leadisaelle","family":"Hosanna Lenguiya","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ghislain","family":"Dzeret Indolo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bani","family":"Reize Vishnou Ampiri","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lucette","family":"Nathalie Macosso","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Igor","family":"Judica\u00ebl Louzolo","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Isaac","family":"Samuel Onyakouang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0009-4122-5541","authenticated-orcid":false,"given":"Jordy","family":"Exauc\u00e9 Lyelet Demboux","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jean Medar","family":"Kankou","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Aristide","family":"Gilbert Nianga","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1414-0237","authenticated-orcid":false,"given":"Avelin F.","family":"Aghokeng","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2288-3196","authenticated-orcid":false,"given":"Vincent Jacobus","family":"Munster","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3843-9396","authenticated-orcid":false,"given":"Fabien","family":"Roch Niama","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2026,4,3]]},"reference":[{"key":"4256_CR1","unstructured":"Multi-country monkeypox outbreak in non-endemic countries. World Health Organization https:\/\/www.who.int\/emergencies\/disease-outbreak-news\/item\/2022-DON385 (2022)."},{"key":"4256_CR2","doi-asserted-by":"publisher","first-page":"273","DOI":"10.1016\/S1473-3099(23)00055-5","volume":"23","author":"D Ulaeto","year":"2023","unstructured":"Ulaeto, D. et al. New nomenclature for mpox (monkeypox) and monkeypox virus clades. Lancet Infect. Dis. 23, 273\u2013275 (2023).","journal-title":"Lancet Infect. Dis."},{"key":"4256_CR3","doi-asserted-by":"publisher","first-page":"2791","DOI":"10.1038\/s41591-024-03130-3","volume":"30","author":"EH Vakaniaki","year":"2024","unstructured":"Vakaniaki, E. H. et al. Sustained human outbreak of a new MPXV clade I lineage in eastern Democratic Republic of the Congo. Nat. Med. 30, 2791\u20132795 (2024).","journal-title":"Nat. Med."},{"key":"4256_CR4","doi-asserted-by":"publisher","first-page":"2012","DOI":"10.3390\/v14092012","volume":"14","author":"JC Riopelle","year":"2022","unstructured":"Riopelle, J. C., Munster, V. J. & Port, J. R. Atypical and unique transmission of monkeypox virus during the 2022 outbreak: an overview of the current state of knowledge. Viruses 14, 2012 (2022).","journal-title":"Viruses"},{"key":"4256_CR5","doi-asserted-by":"publisher","first-page":"16262","DOI":"10.1073\/pnas.1005769107","volume":"107","author":"AW Rimoin","year":"2010","unstructured":"Rimoin, A. W. et al. Major increase in human monkeypox incidence 30 years after smallpox vaccination campaigns cease in the Democratic Republic of Congo. Proc. Natl Acad. Sci. USA 107, 16262\u201316267 (2010).","journal-title":"Proc. Natl Acad. Sci. USA"},{"key":"4256_CR6","doi-asserted-by":"publisher","first-page":"432","DOI":"10.3201\/eid3003.230861","volume":"30","author":"D Djuicy","year":"2024","unstructured":"Djuicy, D. et al. Concurrent clade I and clade II monkeypox virus circulation, Cameroon, 1979\u20132022. Emerg. Infect. Dis. 30, 432 (2024).","journal-title":"Emerg. Infect. 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Lancet 405, 86\u201396 (2025).","journal-title":"Lancet"},{"key":"4256_CR10","doi-asserted-by":"publisher","first-page":"2274","DOI":"10.1016\/S0140-6736(25)01203-6","volume":"405","author":"O Mitja","year":"2025","unstructured":"Mitja, O., Watson-Jones, D., Choi, E. M., Jalloh, M. B. & Sahr, F. Clade IIb mpox outbreak in Sierra Leone. Lancet 405, 2274\u20132275 (2025).","journal-title":"Lancet"},{"key":"4256_CR11","unstructured":"Sandi, D. S. Genomic epidemiology of Mpox virus in Sierra Leone. Virological https:\/\/virological.org\/t\/genomic-epidemiology-of-mpox-virus-in-sierra-leone\/995 (2025)."},{"key":"4256_CR12","doi-asserted-by":"publisher","unstructured":"Kangbai, J. B. et al. Clinical and epidemiological characteristics among probable and confirmed patients with mpox in Sierra Leone reported from January to May 2025. 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Epidemiological and genomic evolution of the ongoing outbreak of clade Ib mpox virus in the eastern Democratic Republic of the Congo. Nat. Med. 31, 1459\u20131463 (2025).","journal-title":"Nat. Med."},{"key":"4256_CR16","doi-asserted-by":"publisher","first-page":"1815","DOI":"10.1016\/S0140-6736(24)02188-3","volume":"404","author":"CK Yinda","year":"2024","unstructured":"Yinda, C. K. et al. Genetic sequencing analysis of monkeypox virus clade I in Republic of the Congo: a cross-sectional, descriptive study. Lancet 404, 1815\u20131822 (2024).","journal-title":"Lancet"},{"key":"4256_CR17","doi-asserted-by":"publisher","first-page":"1135","DOI":"10.1056\/NEJMc2504089","volume":"393","author":"F Koukouikila-Koussounda","year":"2025","unstructured":"Koukouikila-Koussounda, F. et al. Introduction of mpox virus clade Ib into the Republic of the Congo. N. Engl. J. Med. 393, 1135\u20131137 (2025).","journal-title":"N. Engl. J. 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