{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,17]],"date-time":"2026-08-17T05:49:55Z","timestamp":1786945795692,"version":"build-2736575974"},"reference-count":94,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2025,7,17]],"date-time":"2025-07-17T00:00:00Z","timestamp":1752710400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"University of Cape Town\u2019s (UCT) Innovation Builder Fund","award":["IB22-006"],"award-info":[{"award-number":["IB22-006"]}]},{"name":"University of Cape Town\u2019s (UCT) Innovation Builder Fund","award":["19\/80"],"award-info":[{"award-number":["19\/80"]}]},{"name":"National Research Foundation (NRF)","award":["IB22-006"],"award-info":[{"award-number":["IB22-006"]}]},{"name":"National Research Foundation (NRF)","award":["19\/80"],"award-info":[{"award-number":["19\/80"]}]},{"name":"Wild Bird Trust (WBT) for the Cape Parrot Project (CPP)","award":["IB22-006"],"award-info":[{"award-number":["IB22-006"]}]},{"name":"Wild Bird Trust (WBT) for the Cape Parrot Project (CPP)","award":["19\/80"],"award-info":[{"award-number":["19\/80"]}]},{"DOI":"10.13039\/501100001323","name":"UCT Doctoral Research Scholarship, Poliomyelitis Research Foundation (PRF)","doi-asserted-by":"publisher","award":["IB22-006"],"award-info":[{"award-number":["IB22-006"]}],"id":[{"id":"10.13039\/501100001323","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001323","name":"UCT Doctoral Research Scholarship, Poliomyelitis Research Foundation (PRF)","doi-asserted-by":"publisher","award":["19\/80"],"award-info":[{"award-number":["19\/80"]}],"id":[{"id":"10.13039\/501100001323","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Council for Scientific and Industrial Research and the Department of Science and Technology (CSIR-DST)","award":["IB22-006"],"award-info":[{"award-number":["IB22-006"]}]},{"name":"Council for Scientific and Industrial Research and the Department of Science and Technology (CSIR-DST)","award":["19\/80"],"award-info":[{"award-number":["19\/80"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Background\/Objectives: Beak and feather disease virus (BFDV) is the causative agent of psittacine beak and feather disease (PBFD), affecting psittacine birds. There is currently no commercial vaccine or treatment for this disease. This study developed a novel BFDV coat protein mRNA vaccine encapsidated by TMV coat protein to form pseudovirions (PsVs) and tested its immunogenicity alongside BFDV coat protein (CP) subunit and DNA vaccine candidates. Methods: mRNA and BFDV CP subunit vaccine candidates were produced in Nicotiana benthamiana and subsequently purified using PEG precipitation and gradient ultracentrifugation, respectively. The DNA vaccine candidate was produced in E. coli cells harbouring a plasmid with a BFDV1.1mer pseudogenome. Immunogenicity of the vaccine candidates was evaluated in African grey parrot chicks. Results: Successful purification of TMV PsVs harbouring the mRNA vaccine, and of the BFDV-CP subunit vaccine, was confirmed by SDS-PAGE and western blot analysis. TEM analyses confirmed formation of TMV PsVs, while RT-PCR and RT-qPCR cDNA amplification confirmed encapsidation of the mRNA vaccine candidate within TMV particles. Restriction digests verified presence of the BFDV1.1mer genome in the plasmid. Four groups of 5 ten-week-old African grey parrot (Psittacus erithacus) chicks were vaccinated and received two boost vaccinations 2 weeks apart. Blood samples were collected from all four groups on day 14, 28 and 42, and sera were analysed using indirect ELISA, which showed that all vaccine candidates successfully elicited specific anti-BFDV-CP immune responses. The subunit vaccine candidate showed the strongest immune response, indicated by higher binding titres (&gt;6400), followed by the mRNA and DNA vaccine candidates. Conclusions: The candidate vaccines present an important milestone in the search for a protective vaccine against PBFD, and their inexpensive manufacture could considerably aid commercial vaccine development.<\/jats:p>","DOI":"10.3390\/vaccines13070762","type":"journal-article","created":{"date-parts":[[2025,7,17]],"date-time":"2025-07-17T13:00:51Z","timestamp":1752757251000},"page":"762","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Immunogenicity of DNA, mRNA and Subunit Vaccines Against Beak and Feather Disease Virus"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0009-0009-5421-0971","authenticated-orcid":false,"given":"Buyani","family":"Ndlovu","sequence":"first","affiliation":[{"name":"Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town 7701, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9751-3838","authenticated-orcid":false,"given":"Albertha R.","family":"van Zyl","sequence":"additional","affiliation":[{"name":"Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town 7701, South Africa"},{"name":"Centre for Bioprocess Engineering Research, Department of Chemical Engineering, University of Cape Town, Rondebosch, Cape Town 7701, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dirk","family":"Verwoerd","sequence":"additional","affiliation":[{"name":"Parrot Breeding Solutions (PTY) Ltd., Nigel 1491, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8024-9911","authenticated-orcid":false,"given":"Edward P.","family":"Rybicki","sequence":"additional","affiliation":[{"name":"Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town 7701, South Africa"},{"name":"Institute of Infectious Disease and Molecular Medicine, Faculty of Health Sciences, University of Cape Town, Observatory, Cape Town 7925, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8515-9525","authenticated-orcid":false,"given":"Inga I.","family":"Hitzeroth","sequence":"additional","affiliation":[{"name":"Biopharming Research Unit, Department of Molecular and Cell Biology, University of Cape Town, Rondebosch, Cape Town 7701, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,7,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1005","DOI":"10.1099\/jmm.0.000516","article-title":"A high prevalence of beak and feather disease virus in non-psittacine Australian birds","volume":"66","author":"Marenda","year":"2017","journal-title":"J. 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