{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,22]],"date-time":"2026-10-22T07:37:12Z","timestamp":1792654632191,"version":"4.5.0"},"reference-count":61,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2021,11,5]],"date-time":"2021-11-05T00:00:00Z","timestamp":1636070400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100002428","name":"Austrian Science Fund","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100002428","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100002428","name":"Austrian Science Fund","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100002428","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100009818","name":"Amt der Steierm\u00e4rkischen Landesregierung","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100009818","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100019802","name":"BioTechMed-Graz","doi-asserted-by":"publisher","id":[{"id":"10.13039\/501100019802","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Microbiol."],"abstract":"<jats:p>The prevailing pandemic of SARS-CoV-2 highlights the desperate need of alternative vaccine-platforms, which are safe, effective, and can be modified to carry antigens of emerging pathogens. The current SARS-CoV-2 vaccines based on mRNA and adenoviral vector technology meet some of these criteria but still face limitations regarding administration route, mass production, stability, and storage. Herein, we introduce a novel SARS-CoV-2 vaccine candidate based on bacterial outer membrane vesicles (OMVs). <jats:italic>Vibrio cholerae<\/jats:italic> and enterotoxigenic <jats:italic>Escherichia coli<\/jats:italic> (ETEC) have been genetically modified to produce increased amounts of detoxified OMVs decorated with the receptor binding domain (RBD) of the SARS-CoV-2 Spike protein. Intranasal immunization with RBD-decorated OMVs induced not only a robust immune response against the bacterial outer membrane components but also detectable antibody titers against the Spike protein. Cell culture infection assays using a Spike-pseudotyped lentivirus confirmed the presence of SARS-CoV-2 neutralizing antibodies. Highest titers against the SARS-CoV-2 Spike protein and most potent neutralization activity were observed for an alternating immunization regimen using RBD-decorated OMVs from ETEC and <jats:italic>V. cholerae<\/jats:italic> in turn. These results highlight the versatile vaccine applications offered by OMVs <jats:italic>via<\/jats:italic> expression of heterologous antigens in the donor bacterium.<\/jats:p>","DOI":"10.3389\/fmicb.2021.752739","type":"journal-article","created":{"date-parts":[[2021,11,5]],"date-time":"2021-11-05T14:31:51Z","timestamp":1636122711000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":38,"title":["An Intranasal Vaccine Based on Outer Membrane Vesicles Against SARS-CoV-2"],"prefix":"10.3389","volume":"12","author":[{"given":"Himadri B.","family":"Thapa","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anna M.","family":"M\u00fcller","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Andrew","family":"Camilli","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Stefan","family":"Schild","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2021,11,5]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.3390\/pathogens10070788","article-title":"A summary of the SARS-CoV-2 vaccines and technologies available or under development.","volume":"10","author":"Abdulla","year":"2021","journal-title":"Pathogens"},{"key":"B2","doi-asserted-by":"publisher","first-page":"619","DOI":"10.1093\/glycob\/cwx036","article-title":"The direct and indirect effects of glycans on immune function.","volume":"27","author":"Baum","year":"2017","journal-title":"Glycobiology"},{"key":"B3","doi-asserted-by":"publisher","first-page":"4402","DOI":"10.1128\/IAI.00398-10","article-title":"Mucosal immunization with Vibrio cholerae outer membrane vesicles provides maternal protection mediated by antilipopolysaccharide antibodies that inhibit bacterial motility.","volume":"78","author":"Bishop","year":"2010","journal-title":"Infect. 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