{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T14:12:31Z","timestamp":1785420751544,"version":"3.56.0"},"reference-count":35,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2026,5,28]],"date-time":"2026-05-28T00:00:00Z","timestamp":1779926400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Ministry of Science, Technological Development and Innovation of the Republic of Serbia","award":["451-03-136\/2025-03\/200177"],"award-info":[{"award-number":["451-03-136\/2025-03\/200177"]}]},{"award":["451-03-136\/2025-03\/200177"],"award-info":[{"award-number":["451-03-136\/2025-03\/200177"]}],"id":[{"id":"https:\/\/ror.org\/01znas443","id-type":"ROR","asserted-by":"publisher"}]},{"name":"Institute of Virology, Vaccines and Sera \u201cTorlak\u201d"},{"id":[{"id":"https:\/\/ror.org\/0150fxq66","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Vaccines"],"abstract":"<jats:p>Background: The Global Action Plan for Influenza Vaccines, launched by the World Health Organization in 2006, aimed to expand global manufacturing capacity, ensure equitable access to influenza vaccines, and reduce global vaccine shortages. The Institute of Virology, Vaccines and Sera \u201cTorlak\u201d was recognized as a partner and participated in a technology transfer programme to improve national production capabilities. Preclinical studies conducted in 2013 and 2014 provided comprehensive toxicological evidence supporting the safety of the trivalent influenza vaccine manufacturing platform. Nearly a decade later, this validated platform enabled the independent development of a quadrivalent influenza vaccine. Subsequent preclinical studies conducted in accordance with European Medicines Agency guidelines demonstrated preserved immunogenicity despite the inclusion of an additional antigen. Methods: Preclinical evaluation included standard safety and immunogenicity assessments in animal models. Safety assessment included evaluation of systemic parameters (general health status, leukocyte profile, blood biochemistry, and histopathology) and local reactions. Immunogenicity of both trivalent and quadrivalent formulations was assessed using haemagglutination inhibition and microneutralization assays. Results: No significant systemic or local adverse effects were observed. Both trivalent and quadrivalent formulations induced robust immune responses, with immunogenicity comparable to that of corresponding commercial vaccines. Conclusions: These findings confirm the safety profile and demonstrate strong immunogenicity for both the trivalent and quadrivalent formulations, supporting the successful establishment of a national influenza vaccine platform, contributing to increased pandemic preparedness and sustainable influenza vaccine production.<\/jats:p>","DOI":"10.3390\/vaccines14060477","type":"journal-article","created":{"date-parts":[[2026,5,28]],"date-time":"2026-05-28T09:57:43Z","timestamp":1779962263000},"page":"477","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Evolution of National Influenza Vaccine Platform: From Comprehensive Preclinical Safety Validation of Trivalent Influenza Vaccine to Streamlined Immunogenicity of Quadrivalent Formulation"],"prefix":"10.3390","volume":"14","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-1662-0493","authenticated-orcid":false,"given":"Luka","family":"Draga\u010devi\u0107","sequence":"first","affiliation":[{"name":"Institute of Virology, Vaccines and Sera \u201cTorlak\u201d, Vojvode Stepe 458, 11000 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8491-9924","authenticated-orcid":false,"given":"Veljko","family":"Blagojevi\u0107","sequence":"additional","affiliation":[{"name":"Institute of Virology, Vaccines and Sera \u201cTorlak\u201d, Vojvode Stepe 458, 11000 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2115-5901","authenticated-orcid":false,"given":"Marko","family":"Vasi\u0107","sequence":"additional","affiliation":[{"name":"Institute of Virology, Vaccines and Sera \u201cTorlak\u201d, Vojvode Stepe 458, 11000 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2941-9246","authenticated-orcid":false,"given":"Rajna","family":"Mini\u0107","sequence":"additional","affiliation":[{"name":"Institute of Virology, Vaccines and Sera \u201cTorlak\u201d, Vojvode Stepe 458, 11000 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7009-3933","authenticated-orcid":false,"given":"Ivana","family":"\u0106uruvija","sequence":"additional","affiliation":[{"name":"Institute of Virology, Vaccines and Sera \u201cTorlak\u201d, Vojvode Stepe 458, 11000 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8201-2459","authenticated-orcid":false,"given":"Ivana","family":"Priji\u0107","sequence":"additional","affiliation":[{"name":"Institute of Virology, Vaccines and Sera \u201cTorlak\u201d, Vojvode Stepe 458, 11000 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Raisa","family":"Petrovi\u0107","sequence":"additional","affiliation":[{"name":"Institute of Virology, Vaccines and Sera \u201cTorlak\u201d, Vojvode Stepe 458, 11000 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Darko","family":"Rogi\u0107","sequence":"additional","affiliation":[{"name":"Institute of Virology, Vaccines and Sera \u201cTorlak\u201d, Vojvode Stepe 458, 11000 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4074-590X","authenticated-orcid":false,"given":"Irena","family":"\u017divkovi\u0107","sequence":"additional","affiliation":[{"name":"Institute of Virology, Vaccines and Sera \u201cTorlak\u201d, Vojvode Stepe 458, 11000 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,5,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1285","DOI":"10.1016\/S0140-6736(17)33293-2","article-title":"Estimates of global seasonal influenza-associated respiratory mortality: A modelling study","volume":"391","author":"Iuliano","year":"2018","journal-title":"Lancet"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"5086","DOI":"10.1016\/j.vaccine.2007.03.046","article-title":"The annual impact of seasonal influenza in the US: Measuring disease burden and costs","volume":"25","author":"Molinari","year":"2007","journal-title":"Vaccine"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"728","DOI":"10.1016\/j.vaccine.2012.10.111","article-title":"Global production capacity of seasonal influenza vaccine in 2011","volume":"31","author":"Patridge","year":"2013","journal-title":"Vaccine"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"A2","DOI":"10.1016\/j.vaccine.2011.02.079","article-title":"WHO initiative to increase global and equitable access to influenza vaccine in the event of pandemic: Supporting developing country production capacity through technology transfer","volume":"29","author":"Friede","year":"2011","journal-title":"Vaccine"},{"key":"ref_5","unstructured":"World Health Organization (2006). Global Pandemic Influenza Action Plan to Increase Vaccine Supply, WHO Press."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1335","DOI":"10.1056\/NEJMra1208802","article-title":"Pandemic Preparedness and Response\u2014Lessons from the H1N1 influenza of 2009","volume":"370","author":"Fineberg","year":"2014","journal-title":"N. Engl. J. Med."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"81","DOI":"10.4161\/hv.8.1.17623","article-title":"The rationale for quadrivalent influenza vaccines","volume":"8","author":"Ambrose","year":"2012","journal-title":"Hum. Vaccin. Immunother."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"5572","DOI":"10.1016\/j.vaccine.2013.08.069","article-title":"Safety and immunogenicity of a quadrivalent inactivated influenza vaccine in adults","volume":"47","author":"Pepin","year":"2013","journal-title":"Vaccine"},{"key":"ref_9","unstructured":"World Health Organization (2005). Recommendations for the Production and Control of Influenza Vaccine (Inactivated), World Health Organization. WHO Technical Report Series No. 927, Annex 3."},{"key":"ref_10","unstructured":"European Medicines Agency (2017). Guideline on Influenza Vaccines\u2014Quality Module (EMA\/CHMP\/BWP\/310834\/2012 Rev. 1)."},{"key":"ref_11","unstructured":"European Directorate for the Quality of Medicines & HealthCare (2020). Influenza vaccine (inactivated, split virion or surface antigen), European Pharmacopoeia."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Skerritt, J.H., Tucek-Szabo, C., Sutton, B., and Nolan, T. (2024). The Platform Technology Approach to mRNA Product Development and Regulation. Vaccine, 12.","DOI":"10.20944\/preprints202404.1060.v1"},{"key":"ref_13","unstructured":"European Medicines Agency (2014). Guideline on Influenza Vaccines\u2014Non-Clinical and Clinical Module, EMA\/CHMP\/VWP\/457259\/2014."},{"key":"ref_14","unstructured":"World Health Organization (2007). Expert Committee on Biological Standardization: Regulatory Preparedness for Human Pandemic Influenza Vaccines, World Health Organization."},{"key":"ref_15","unstructured":"EudraLex (2011). The Rules Governing Medicinal Products in the European Union, Volume 4: EU Guidelines for Good Manufacturing Practice for Medicinal Products for Human and Veterinary Use."},{"key":"ref_16","unstructured":"European Medicines Evaluation Agency (1997). Note for Guidance on Preclinical Pharmacological and Toxicological Testing of Vaccines (CPMP\/SWP\/465\/95)."},{"key":"ref_17","unstructured":"European Medicines Evaluation Agency (2000). Note for Guidance on Repeated Dose Toxicity Studies (CPMP\/SWP\/1042\/99)."},{"key":"ref_18","unstructured":"European Medicines Agency (2009). ICH Guideline M3(R2) on Non-Clinical Safety Studies for the Conduct of Human Clinical Trials and Marketing Authorisation for Pharmaceuticals (EMA\/CPMP\/ICH\/286\/1995)."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"166","DOI":"10.1016\/S0273-2300(03)00089-8","article-title":"Local tolerance testing of parenteral drugs: How to put into practice","volume":"38","author":"Jochims","year":"2003","journal-title":"Regul. Toxicol. Pharmacol."},{"key":"ref_20","unstructured":"European Medicines Agency (2001). Note for Guidance on Non-Clinical Local Tolerance Testing of Medicinal Products (CPMP\/SWP\/2145\/00)."},{"key":"ref_21","unstructured":"(2008). Principles of Good Laboratory Practice (GLP), Official Gazette of the Republic of Serbia."},{"key":"ref_22","first-page":"5546","article-title":"Sexual diergism in antibody response to whole virus trivalent inactivated influenza vaccine in outbred mice","volume":"42","author":"Bufan","year":"2015","journal-title":"Vaccine"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"18","DOI":"10.1016\/j.biologicals.2018.01.007","article-title":"Sex bias in mouse humoral immune response to influenza vaccine depends on the vaccine type","volume":"52","author":"Bufan","year":"2018","journal-title":"Biologicals"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Garcia-Dominguez, D., Henry, C., Ma, L., Jani, H., Amato, N.J., Manning, T., Freyn, A., Davis, H., Hsiao, C.J., and Li, M. (2022). Altering the mRNA-1273 dosing interval impacts the kinetics, quality, and magnitude of immune responses in mice. Front. Immunol., 13.","DOI":"10.3389\/fimmu.2022.948335"},{"key":"ref_25","unstructured":"(2010). Directive 2010\/63\/EU of the European Parliament and of the Council of 22 September 2010 on the Protection of Animals Used for Scientific Purposes, Official Journal of the European Union, L 276, 20 October 2010."},{"key":"ref_26","unstructured":"(2024). Commission Delegated Directive (EU) 2024\/1262 of 13 March 2024 Amending Directive 2010\/63\/EU of the European Parliament and of the Council as Regards the Requirements for Establishments and for the Care and Accommodation of Animals, and as Regards the Methods of Killing Animals, Official Journal of the European Union, L 1262, 15 May 2024."},{"key":"ref_27","unstructured":"(1986). European Convention for the Protection of Vertebrate Animals Used for Experimental and Other Scientific Purposes (ETS No. 123), Council of Europe."},{"key":"ref_28","unstructured":"(2006). Revised Appendix A to the European Convention for the Protection of Vertebrate Animals Used for Experimental and Other Scientific Purposes (ETS No. 123): Guidelines for Accommodation and Care of Animals Used for Experimental and Other Scientific Purposes, Council of Europe. amendments entered into force 2007."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"359","DOI":"10.1111\/cyt.12323","article-title":"Guidelines for May Gr\u00fcnwald Giemsa staining in haematology and non gynaecological cytopathology: Recommendations of the French Society of Clinical Cytology (SFCC) and the French Association for Quality Assurance in Anatomic and Cytologic Pathology (AFAQAP)","volume":"27","author":"Piaton","year":"2016","journal-title":"Cytopathology"},{"key":"ref_30","unstructured":"Jensen, H.E. (2011). Necropsy of Rodents (Rat, Mouse, Guinea Pig, and Hamster). Necropsy: A Handbook and Atlas, Biofolia."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Plitnick, L.M. (2013). Global Regulatory Guidelines for Vaccines. Nonclinical Development of Novel Biologics, Biosimilars, Vaccines and Specialty Biologics, Academic Press.","DOI":"10.1016\/B978-0-12-394810-6.00009-5"},{"key":"ref_32","unstructured":"Bancroft, J.D., and Gamble, M. (2008). Theory and Practice of Histological Techniques, Elsevier\/Churchill Livingstone. [8th ed.]."},{"key":"ref_33","unstructured":"World Health Organisation (2011). Manual for the Laboratory Diagnosis and Virological Surveillance of Influenza, World Health Organisation. Available online: https:\/\/www.who.int\/publications\/i\/item\/manual-for-the-laboratory-diagnosis-and-virological-surveillance-of-influenza."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"751","DOI":"10.1080\/01926230701595300","article-title":"Society of Toxicologic Pathology position paper: Organ weight recommendations for toxicology studies","volume":"35","author":"Sellers","year":"2007","journal-title":"Toxicol. Pathol."},{"key":"ref_35","doi-asserted-by":"crossref","unstructured":"Badruzzaman, A.T.M., Cheng, Y.C., Sung, W.C., and Lee, M.S. (2024). Insect Cell-Based Quadrivalent Seasonal Influenza Virus-like Particles Vaccine Elicits Potent Immune Responses in Mice. Vaccines, 12.","DOI":"10.3390\/vaccines12060667"}],"container-title":["Vaccines"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-393X\/14\/6\/477\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,28]],"date-time":"2026-05-28T10:17:10Z","timestamp":1779963430000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-393X\/14\/6\/477"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,5,28]]},"references-count":35,"journal-issue":{"issue":"6","published-online":{"date-parts":[[2026,6]]}},"alternative-id":["vaccines14060477"],"URL":"https:\/\/doi.org\/10.3390\/vaccines14060477","relation":{},"ISSN":["2076-393X"],"issn-type":[{"value":"2076-393X","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,5,28]]}}}