{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,9]],"date-time":"2026-06-09T08:07:37Z","timestamp":1780992457871,"version":"3.54.1"},"reference-count":45,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2022,8,31]],"date-time":"2022-08-31T00:00:00Z","timestamp":1661904000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"National Health Research Institutes, Taiwan","award":["# 110-2327-B-400-004"],"award-info":[{"award-number":["# 110-2327-B-400-004"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Viruses"],"abstract":"<jats:p>Human infections with avian-origin H7N9 influenza A viruses were first reported in China, and an approximately 38% human mortality rate was described across six waves from February 2013 to September 2018. Vaccination is one of the most cost-effective ways to reduce morbidity and mortality during influenza epidemics and pandemics. Egg-based platforms for the production of influenza vaccines are labor-intensive and unable to meet the surging demand during pandemics. Therefore, cell culture-based technology is becoming the alternative strategy for producing influenza vaccines. The current influenza H7N9 vaccine virus (NIBRG-268), a reassortant virus from A\/Anhui\/1\/2013 (H7N9) and egg-adapted A\/PR\/8\/34 (H1N1) viruses, could grow efficiently in embryonated eggs but not mammalian cells. Moreover, a freezing-dry formulation of influenza H7N9 vaccines with long-term stability will be desirable for pandemic preparedness, as the occurrence of influenza H7N9 pandemics is not predictable. In this study, we adapted a serum-free anchorage-independent suspension Madin-Darby Canine Kidney (MDCK) cell line for producing influenza H7N9 vaccines and compared the biochemical characteristics and immunogenicity of three influenza H7N9 vaccine antigens produced using the suspension MDCK cell-based platform without freeze-drying (S-WO-H7N9), the suspension MDCK cell-based platform with freeze-drying (S-W-H7N9) or the egg-based platform with freeze-drying (E-W-H7N9). We demonstrated these three vaccine antigens have comparable biochemical characteristics. In addition, these three vaccine antigens induced robust and comparable neutralizing antibody (NT; geometric mean between 1016 and 4064) and hemagglutinin-inhibition antibody (HI; geometric mean between 640 and 1613) titers in mice. In conclusion, the serum-free suspension MDCK cell-derived freeze-dried influenza H7N9 vaccine is highly immunogenic in mice, and clinical development is warranted.<\/jats:p>","DOI":"10.3390\/v14091937","type":"journal-article","created":{"date-parts":[[2022,9,1]],"date-time":"2022-09-01T03:55:38Z","timestamp":1662004538000},"page":"1937","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":6,"title":["Characterization and Immunogenicity of Influenza H7N9 Vaccine Antigens Produced Using a Serum-Free Suspension MDCK Cell-Based Platform"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1973-099X","authenticated-orcid":false,"given":"Min-Yuan","family":"Chia","sequence":"first","affiliation":[{"name":"Department of Veterinary Medicine, National Chung Hsing University, Taichung 40227, Taiwan"},{"name":"National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan 35053, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3064-0178","authenticated-orcid":false,"given":"Chun-Yang","family":"Lin","sequence":"additional","affiliation":[{"name":"National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan 35053, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7179-6144","authenticated-orcid":false,"given":"Po-Ling","family":"Chen","sequence":"additional","affiliation":[{"name":"National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan 35053, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chia-Chun","family":"Lai","sequence":"additional","affiliation":[{"name":"National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan 35053, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tsai-Chuan","family":"Weng","sequence":"additional","affiliation":[{"name":"National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan 35053, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3445-6036","authenticated-orcid":false,"given":"Wang-Chou","family":"Sung","sequence":"additional","affiliation":[{"name":"National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan 35053, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4501-8645","authenticated-orcid":false,"given":"Alan Yung-Chih","family":"Hu","sequence":"additional","affiliation":[{"name":"National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan 35053, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Min-Shi","family":"Lee","sequence":"additional","affiliation":[{"name":"National Institute of Infectious Diseases and Vaccinology, National Health Research Institutes, Zhunan 35053, Taiwan"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,8,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"241","DOI":"10.1038\/nature12515","article-title":"The genesis and source of the H7N9 influenza viruses causing human infections in China","volume":"502","author":"Lam","year":"2013","journal-title":"Nature"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"106","DOI":"10.1016\/j.coviro.2016.01.020","article-title":"Emergence and development of H7N9 influenza viruses in China","volume":"16","author":"Zhu","year":"2016","journal-title":"Curr. 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