{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T09:24:49Z","timestamp":1787045089566,"version":"build-2736575974"},"reference-count":35,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T00:00:00Z","timestamp":1787011200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"StemiRNA Therapeutics"},{"id":[{"id":"https:\/\/ror.org\/044r4fv50","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Background\/Objectives: Messenger RNA vaccines can induce strong immune responses, but delivery, biodistribution, and storage stability remain important considerations. We evaluated the safety and immunogenicity of SW-BIC-213, a Lipo-Polyplex (LPP)-based mRNA vaccine against SARS-CoV-2, in healthy adults in Laos. Methods: We conducted a seamless phase 1\/2 clinical trial in healthy adults. Phase 1 enrolled adults aged 18\u201360 years in an open-label, single-arm dose-escalation study; phase 2 enrolled adults aged \u226518 years in a randomized, double-blind, placebo-controlled study. Participants received two doses 21 days apart. The primary endpoints were safety in phase 1 and safety and immunogenicity in phase 2. Results: In phase 1, 41 participants received 25 or 45 \u03bcg of SW-BIC-213. In phase 2, 480 participants were randomized in a 2:2:1 ratio to receive 25 \u03bcg, 45 \u03bcg, or placebo. All phase 1 adverse reactions were grade 1 or 2; grade 3 reactions in phase 2 were limited to transient fever. At 14 days after the second dose, pseudovirus neutralizing-antibody seroconversion exceeded 99% against wild-type virus, 98% against Delta, 84% against Omicron BA.1, and 88% against BA.2. Neutralizing-antibody titers were higher in both vaccine groups than in the placebo group (p &lt; 0.0001). Conclusions: Two doses of SW-BIC-213 showed an acceptable safety profile and substantial humoral immunogenicity in healthy adults aged \u226518 years.<\/jats:p>","DOI":"10.3390\/vaccines14080708","type":"journal-article","created":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T08:08:41Z","timestamp":1787040521000},"page":"708","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Safety and Immunogenicity of SW-BIC-213, a Modified COVID-19 Lipo-Polyplex mRNA Vaccine, in Laotian Healthy Adults Aged 18 Years and Above: A Phase 1\/2 Trial"],"prefix":"10.3390","volume":"14","author":[{"given":"Ying","family":"Yuan","sequence":"first","affiliation":[{"name":"Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yichao","family":"Zeng","sequence":"additional","affiliation":[{"name":"Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mingxiong","family":"Zhu","sequence":"additional","affiliation":[{"name":"Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ziyu","family":"Sun","sequence":"additional","affiliation":[{"name":"Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Weiwei","family":"Xu","sequence":"additional","affiliation":[{"name":"Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yinran","family":"Hu","sequence":"additional","affiliation":[{"name":"School of Basic Medical Sciences, Shandong University, Baotuquan Campus, Jinan 250100, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Guanzhou","family":"Liu","sequence":"additional","affiliation":[{"name":"School of Life Sciences, Nanjing University, Xianlin Campus, Nanjing 210093, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mingyun","family":"Shen","sequence":"additional","affiliation":[{"name":"School of Biomedical Outstanding Engineers, China Pharmaceutical University Jiangning Campus, Nanjing 211198, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7934-9269","authenticated-orcid":false,"given":"Chen","family":"Yang","sequence":"additional","affiliation":[{"name":"Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Di","family":"Gao","sequence":"additional","affiliation":[{"name":"Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou 310024, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,18]]},"reference":[{"key":"ref_1","first-page":"157","article-title":"WHO Declares COVID-19 a Pandemic","volume":"91","author":"Cucinotta","year":"2020","journal-title":"Acta Bio Med. 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