{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"institution":[{"name":"medRxiv"}],"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T15:08:51Z","timestamp":1785424131226,"version":"3.56.0"},"posted":{"date-parts":[[2026,6,8]]},"group-title":"Infectious Diseases (except HIV\/AIDS)","reference-count":36,"publisher":"openRxiv","license":[{"start":{"date-parts":[[2026,6,8]],"date-time":"2026-06-08T00:00:00Z","timestamp":1780876800000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"name":"EDCTP2","award":["RIA2017S-2014 - PREVAC-UP"],"award-info":[{"award-number":["RIA2017S-2014 - PREVAC-UP"]}]},{"award":["115854, EBOVAC1"],"award-info":[{"award-number":["115854, EBOVAC1"]}],"id":[{"id":"https:\/\/ror.org\/019af4n30","id-type":"ROR","asserted-by":"publisher"}]},{"name":"NCI Information Systems","award":["HHSN261201500003I"],"award-info":[{"award-number":["HHSN261201500003I"]}]},{"name":"NCI Information Systems","award":["75N91019D00024"],"award-info":[{"award-number":["75N91019D00024"]}]},{"id":[{"id":"https:\/\/ror.org\/02vjkv261","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"accepted":{"date-parts":[[2026,6,8]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                <jats:sec>\n                  <jats:title>Background<\/jats:title>\n                  <jats:p>The World Health Organization has expanded its recommendations for prophylactic Ebola vaccination for at-risk populations. Durable vaccine-induced immunity is important for sustaining outbreak preparedness in regions with recurrent Ebola virus disease (EVD). We assessed five-year persistence of vaccine-induced immune responses in adults and children from the PREVAC trial.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Methods<\/jats:title>\n                  <jats:p>\n                    Two large randomised phase 2 trials (\n                    <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" ext-link-type=\"clintrialgov\" xlink:href=\"NCT02876328\">NCT02876328<\/jats:ext-link>\n                    ), in adults and children aged \u2265 1 year, were conducted in four west African countries. Participants were randomly assigned to placebo or to one of three Ebola vaccine strategies: Ad26.ZEBOV followed by MVA-BN-Filo at 56 days; rVSV\u0394G-ZEBOV-GP followed by placebo; or rVSV\u0394G-ZEBOV-GP followed by a homologous booster dose at 56 days. After 12 months of follow-up, the primary results were published, participants unblinded to their vaccine assignment, and follow-up continued for 60 months. After Month 24, placebo group recipients were offered active vaccination. Anti\u2013Ebola virus glycoprotein Immunoglobulin G (IgG) concentrations were measured for 5 years.\n                  <\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Findings<\/jats:title>\n                  <jats:p>1401 adults and 1401 children were initially randomized, and 1315 (93.9%) adults and 1322 (94.4%) children attended at least one long-term visit. Retention was high, with 95% followed beyond 1 year and 83% completion at 5-year follow-up. For the three vaccine strategies, antibody geometric mean concentrations (GMC) declined modestly between Months 12 and 24, followed by a stable plateau from Months 24 to 60. At Month 60, antibody GMC were higher in the rVSV-based groups (1099 and 1216 EU\/ml for adults; 1982 and 2347 EU\/ml for children) than in the Ad26.ZEBOV, MVA-BN-Filo group (252 adults and 645 EUml children). Antibody persistence at Month 60 was heterogeneous, varying by age, sex, country, and baseline IgG concentration.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Interpretation<\/jats:title>\n                  <jats:p>Licensed Ebola vaccines induced sustained antibody responses in adults and children for up to 5 years. While the protective antibody level is unknown, these data demonstrate long-lasting immune responses from currently employed vaccine strategies.<\/jats:p>\n                <\/jats:sec>\n                <jats:sec>\n                  <jats:title>Trial registration numbers<\/jats:title>\n                  <jats:p>\n                    <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" ext-link-type=\"uri\" xlink:href=\"http:\/\/ClinicalTrials.gov\">ClinicalTrials.gov<\/jats:ext-link>\n                    number,\n                    <jats:ext-link xmlns:xlink=\"http:\/\/www.w3.org\/1999\/xlink\" ext-link-type=\"clintrialgov\" xlink:href=\"NCT02876328\">NCT02876328<\/jats:ext-link>\n                    ; EudraCT number 2017-001798-18; and Pan African Clinical Trials Registry number, PACTR201712002760250.\n                  <\/jats:p>\n                <\/jats:sec>","DOI":"10.64898\/2026.05.29.26354050","type":"posted-content","created":{"date-parts":[[2026,6,8]],"date-time":"2026-06-08T23:10:16Z","timestamp":1780960216000},"source":"Crossref","is-referenced-by-count":0,"title":["Five-year immunogenicity and safety follow-up of the PREVAC randomized Trial of Vaccines for Zaire Ebola Virus Disease"],"prefix":"10.64898","author":[{"given":"Abdoul Habib","family":"Beavogui","sequence":"first","affiliation":[{"name":"Centre National de Formation et de Recherche en Sant\u00e9 Rurale de Maferinyah, Maferinyah, Guinea"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Seydou","family":"Doumbia","sequence":"additional","affiliation":[{"name":"University Clinical Research Center (UCRC), University of Sciences, Techniques and Technologies of Bamako (USTTB), Bamako, Mali"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mark","family":"Kieh","sequence":"additional","affiliation":[{"name":"Partnership for Research on Ebola Virus in Liberia (PREVAIL), Monrovia, Liberia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bailah","family":"Leigh","sequence":"additional","affiliation":[{"name":"College of Medicine and Allied Health Sciences (COMAHS), University of Sierra Leone, Freetown, Sierra Leone"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Samba","family":"Sow","sequence":"additional","affiliation":[{"name":"Center for Vaccine Development and Global Health, University of Maryland School of Medicine, 685 West Baltimore Street Baltimore, MD 21201-1509, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Edouard","family":"Lhomme","sequence":"additional","affiliation":[{"name":"Univ. Bordeaux, INSERM, Institut Bergoni\u00e9, CHU de Bordeaux, CIC 1401, Euclid\/F-CRIN clinical trials platform and U1219 BPH, Inria, Sistm, F-33000 Bordeaux, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Safaa","family":"Ben-Farhat","sequence":"additional","affiliation":[{"name":"Univ. Bordeaux, INSERM, Institut Bergoni\u00e9, CHU de Bordeaux, CIC 1401, Euclid\/F-CRIN clinical trials platform, F-33000 Bordeaux, France"},{"name":"Univ. Bordeaux, INSERM, MART, UMS 54, F-33000 Bordeaux, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Natasha","family":"Dubois Cauwelaert","sequence":"additional","affiliation":[{"name":"ANRS Emerging Infectious Diseases, Paris, France"},{"name":"French Institute for Health and Medical Research (INSERM), 75013 Paris, France"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C\u00e9line","family":"Roy","sequence":"additional","affiliation":[{"name":"Univ. 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