{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T05:13:51Z","timestamp":1787030031714,"version":"build-2736575974"},"reference-count":28,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2025,5,30]],"date-time":"2025-05-30T00:00:00Z","timestamp":1748563200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Bavarian Nordic","award":["850450"],"award-info":[{"award-number":["850450"]}]},{"name":"Bavarian Nordic","award":["ERC-2019-STG"],"award-info":[{"award-number":["ERC-2019-STG"]}]},{"name":"European Research Council","award":["850450"],"award-info":[{"award-number":["850450"]}]},{"name":"European Research Council","award":["ERC-2019-STG"],"award-info":[{"award-number":["ERC-2019-STG"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Background: The MVA-BN vaccine is considered effective for preventing mpox in key populations, based on observational studies, though no randomized trials have yet confirmed its effectiveness. Observational studies published to date rely on retrospective analyses of routine data, often missing information on relevant risk factors for mpox. Methods: Multi-country target trial emulation study with prospective data collection. Between 1 September 2022 and 15 June 2023, we recruited individuals eligible for mpox vaccination based on clinical history and exposure behaviors via healthcare centers and social venues in Spain, Peru, Panama, and Chile. Vaccinated individuals were paired with unvaccinated counterparts matched by mpox risk factors, country, recruitment date, and age. Follow-up continued via periodic surveys until 31 March 2024. The primary endpoint was symptomatic mpox occurrence \u226514 days post-vaccination. Results: The primary analysis included 1028 individuals (514 vaccinated, 514 unvaccinated) with a median follow-up time of 9.3 months (IQR 4.7\u201313.7). Mpox occurred in eight participants (0.8%): three vaccinated and five unvaccinated (HR 0.6; 95% CI 0.21\u20131.70). Adverse reactions were reported by 731 (49.6%) participants, predominantly skin reactions (703\/1475; 47.7%), while systemic reactions occurred in 107 (7.3%). Long-lasting erythema at the injection site was reported in 450\/1058 (42.5%) participants, persisting &gt;6 months in 107 of them (23.8%). Conclusions: The low incidence of mpox during the study period resulted in a limited number of endpoint events, precluding robust conclusions on the efficacy of the MVA-BN vaccine as pre-exposure prevention for mpox. However, our analysis, which accounted for key confounders such as exposure behaviors, yielded results consistent with previous studies suggesting the effectiveness of the vaccine in the mpox setting.<\/jats:p>","DOI":"10.3390\/vaccines13060594","type":"journal-article","created":{"date-parts":[[2025,6,2]],"date-time":"2025-06-02T11:40:32Z","timestamp":1748864432000},"page":"594","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Target Trial Emulation of the Modified Vaccinia Ankara-Bavarian Nordic Vaccine for Pre-Exposure Mpox Prevention in At-Risk Populations"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2581-8864","authenticated-orcid":false,"given":"Clara","family":"Su\u00f1er","sequence":"first","affiliation":[{"name":"Skin NTDs and STI Section, Fight Infections Foundation, Germans Trias i Pujol University Hospital, 08916 Badalona, Spain"},{"name":"ISGlobal, Cl\u00ednic Hospital, University of Barcelona, 08036 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0009-1095-4039","authenticated-orcid":false,"given":"Roser","family":"Escrig-Sarreta","sequence":"additional","affiliation":[{"name":"Skin NTDs and STI Section, Fight Infections Foundation, Germans Trias i Pujol University Hospital, 08916 Badalona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9662-9537","authenticated-orcid":false,"given":"Cristina","family":"Galv\u00e1n-Casas","sequence":"additional","affiliation":[{"name":"Skin NTDs and STI Section, Fight Infections Foundation, Germans Trias i Pujol University Hospital, 08916 Badalona, Spain"},{"name":"M\u00f3stoles University Hospital, 28935 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3832-1657","authenticated-orcid":false,"given":"Eduardo","family":"Matos","sequence":"additional","affiliation":[{"name":"Infectology Department, Arzobispo Loayza National Hospital, Lima 15082, Peru"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7712-0444","authenticated-orcid":false,"given":"Amanda","family":"Gabster","sequence":"additional","affiliation":[{"name":"The Gorgas Memorial Institute for Health Studies, Panama City 0801, Panama"},{"name":"National Research System, National Secretariat of Science, Technology and Innovation, Panama City 0801, Panama"},{"name":"Center of Population Sciences for Health Empowerment, College of Nursing, Florida State University, Tallahassee, FL 32306, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marcelo","family":"Wolff","sequence":"additional","affiliation":[{"name":"San Borja Arriar\u00e1n Hospital, Arriar\u00e1n Foundation, Santiago de Chile 8360160, Chile"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dan","family":"Ouchi","sequence":"additional","affiliation":[{"name":"Skin NTDs and STI Section, Fight Infections Foundation, Germans Trias i Pujol University Hospital, 08916 Badalona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrea","family":"Alemany","sequence":"additional","affiliation":[{"name":"Skin NTDs and STI Section, Fight Infections Foundation, Germans Trias i Pujol University Hospital, 08916 Badalona, Spain"},{"name":"ISGlobal, Cl\u00ednic Hospital, University of Barcelona, 08036 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hugo","family":"S\u00e1nchez","sequence":"additional","affiliation":[{"name":"Recruitment and Retention Area, Center for Technological, Biomedical and Environmental Research (CITBM), Mayor de San Marcos National University, Lima 07006, Peru"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sandra","family":"Huaman","sequence":"additional","affiliation":[{"name":"Comprehensive Medical Center Semedic, Lima 15001, Peru"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dixennia","family":"Bejarano","sequence":"additional","affiliation":[{"name":"The Gorgas Memorial Institute for Health Studies, Panama City 0801, Panama"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lourdes","family":"Carr\u00e9s-Esteve","sequence":"additional","affiliation":[{"name":"Fira BCN Vaccination Centre, Catalan Health Institute, 08007 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Cristina","family":"Santiago-Fern\u00e1ndez","sequence":"additional","affiliation":[{"name":"Fira BCN Vaccination Centre, Catalan Health Institute, 08007 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Javier","family":"Corral-Rubio","sequence":"additional","affiliation":[{"name":"General Surgery Department, Germans Trias i Pujol University Hospital, 08916 Badalona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Adri\u00e0","family":"Mendoza","sequence":"additional","affiliation":[{"name":"BCN CheckPoint, Projecte dels NOMS Hispanosida, 08015 Barcelona, Spain"},{"name":"Germans Trias i Pujol University Hospital, 08916 Badalona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2136-0702","authenticated-orcid":false,"given":"\u00c0ngel","family":"Rivero","sequence":"additional","affiliation":[{"name":"BCN CheckPoint, Projecte dels NOMS Hispanosida, 08015 Barcelona, Spain"},{"name":"Germans Trias i Pujol University Hospital, 08916 Badalona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vicente","family":"Descalzo","sequence":"additional","affiliation":[{"name":"Drassanes-Vall d\u2019Hebron STI Unit, 08001 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2684-3431","authenticated-orcid":false,"given":"Eva","family":"Orviz","sequence":"additional","affiliation":[{"name":"Sandoval Health Center, Health Research Institute of the San Carlos Clinical Hospital (IdISSC), San Carlos Clinical Hospital, 28040 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3372-6134","authenticated-orcid":false,"given":"H\u00e9ctor","family":"Mart\u00ednez-Riveros","sequence":"additional","affiliation":[{"name":"Centre of Epidemiological Studies on Sexually Transmitted Infections and AIDS of Catalunya (CEEISCAT), Department of Health, Government of Catalonia, 08916 Badalona, Spain"},{"name":"Biomedical Research Center Network for Epidemiology and Public Health (CIBERESP), Instituto de Salud Carlos III, 28029 Madrid, Spain"},{"name":"Germans Trias i Pujol Research Institute (IGTP), Campus Can Ruti, 08916 Badalona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9215-4378","authenticated-orcid":false,"given":"Leonardo","family":"M\u00e9ndez-Boo","sequence":"additional","affiliation":[{"name":"Primary Care Services Information System (SISAP), Institut Catal\u00e0 de la Salut (ICS), 08007 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Carmen","family":"Cabezas","sequence":"additional","affiliation":[{"name":"Public Health Secretary, Health Department of the Government of Catalonia, 08028 Barcelona, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Araceli","family":"Arce-Arn\u00e1ez","sequence":"additional","affiliation":[{"name":"Direcci\u00f3n General de Salud P\u00fablica, Comunidad de Madrid Consejeria de Sanidad, 28009 Madrid, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7585-4743","authenticated-orcid":false,"given":"Michael","family":"Marks","sequence":"additional","affiliation":[{"name":"Clinical Research Department, London School of Hygiene and Tropical Medicine, London WC1E 7HT, UK"},{"name":"Hospital for Tropical Diseases, Universtiy College London Hospital, London WC1E 6JB, UK"},{"name":"Division of Infection and Immunity, University College London, London WC1E 6BT, UK"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Oriol","family":"Mitj\u00e0","sequence":"additional","affiliation":[{"name":"Skin NTDs and STI Section, Fight Infections Foundation, Germans Trias i Pujol University Hospital, 08916 Badalona, Spain"},{"name":"Department of Medicine, Autonomous University of Barcelona, Bellaterra, Cerdanyola del Vall\u00e9s, 08193 Barcelona, Spain"},{"name":"Chair of Infectious Diseases and Immunity, Vic University-Catalonia Central University, 08500 Vic, Spain"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"name":"REMAIN Study Group","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,5,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"60","DOI":"10.1016\/S0140-6736(22)02075-X","article-title":"Monkeypox","volume":"401","author":"Ogoina","year":"2023","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"661","DOI":"10.1016\/S0140-6736(22)01436-2","article-title":"Clinical presentation and virological assessment of confirmed human monkeypox virus cases in Spain: A prospective observational cohort study","volume":"400","author":"Alemany","year":"2022","journal-title":"Lancet"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Shafaati, M., Forghani, 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