{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,17]],"date-time":"2026-09-17T15:29:33Z","timestamp":1789658973092,"version":"4.0.1"},"reference-count":39,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2026,9,15]],"date-time":"2026-09-15T00:00:00Z","timestamp":1789430400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000046","name":"National Research Council of Canada","doi-asserted-by":"publisher","award":["A1-020810-01-01-01"],"award-info":[{"award-number":["A1-020810-01-01-01"]}],"id":[{"id":"10.13039\/501100000046","id-type":"DOI","asserted-by":"publisher"}]},{"award":["A1-020810-01-01-01"],"award-info":[{"award-number":["A1-020810-01-01-01"]}],"id":[{"id":"https:\/\/ror.org\/04mte1k06","id-type":"ROR","asserted-by":"publisher"}]},{"name":"Canadian Institute of Health Research","award":["170355"],"award-info":[{"award-number":["170355"]}],"id":[{"id":"https:\/\/ror.org\/01gavpb45","id-type":"ROR","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Viruses"],"abstract":"<jats:p>Influenza A viruses remain a persistent global health threat due to their ability to mutate and evade host immune defences, a process largely driven by changes in hemagglutinin (HA). HA is a glycoprotein present on the surface of influenza virions and plays a critical role in viral entry into host cells by binding to cellular receptors. In this study, 23 HA5 protein sequences from various influenza viral strains collected from wild birds, seagulls, ducks, geese, and chickens, as well as from humans in mainland China during the period from 2023 to 2024, were analyzed for mass-charge patterns by our predictive modelling algorithm to understand the nonlinear trend of viral evolution, particularly regarding their antigenic drift and immune escape potential. Two critical regions in HA5 proteins were identified and analyzed. The first region is a \u201cmutable zone\u201d (the negative gravity centre identified by mass-charge pattern analysis), which frequently accumulates multiple mutations. This leads to antigenic drift and instability, enabling the virus to evade pre-existing herd immunity. Analyzing and monitoring mass-charge changes may help predict the evolutionary trend of the viruses and the emergence of future variants in these regions where the viruses were collected, thereby informing the design and development of vaccines for the viruses analyzed and related strains. The second region is a \u201cstable core\u201d (positive gravity centre), a highly conserved region essential for viral function. Due to its conservation across strains, it may represent a promising target for developing universal vaccines and broad-spectrum antibodies capable of conferring protection against multiple variants simultaneously for the viruses analyzed and related strains. In summary, our analyses, with a predictive modelling algorithm for mass-charge patterns of HA5 protein sequences, provide a novel metric for viral evolution and evaluating the immune evasion potential, and offer a strategic framework for designing vaccines against the viruses analyzed and related strains.<\/jats:p>","DOI":"10.3390\/v18091025","type":"journal-article","created":{"date-parts":[[2026,9,15]],"date-time":"2026-09-15T18:23:53Z","timestamp":1789496633000},"page":"1025","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Analysis of HA5 Hemagglutinins from Influenza A Viruses for Mass-Charge Patterns to Understand Antigenic Drift Related to Immune Escape"],"prefix":"10.3390","volume":"18","author":[{"given":"Wenhao","family":"Zhang","sequence":"first","affiliation":[{"name":"School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing 211166, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xinran","family":"Wu","sequence":"additional","affiliation":[{"name":"School of Medical Imaging, Nanjing Medical University, Nanjing 211166, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rui","family":"Zhu","sequence":"additional","affiliation":[{"name":"School of Rehabilitation Medicine, Nanjing Medical University, Nanjing 211166, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xinyi","family":"Pan","sequence":"additional","affiliation":[{"name":"Faculty of Engineering, University of Ottawa, Ottawa, ON K1H 8M5, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Shancheng","family":"Yu","sequence":"additional","affiliation":[{"name":"School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing 211166, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9564-165X","authenticated-orcid":false,"given":"Jie","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Biomedical Engineering and Informatics, Nanjing Medical University, Nanjing 211166, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jun Steed","family":"Huang","sequence":"additional","affiliation":[{"name":"School of Computer Science, Carleton University, Ottawa, ON K1S 5B6, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6412-8124","authenticated-orcid":false,"given":"Wandong","family":"Zhang","sequence":"additional","affiliation":[{"name":"Human Health Therapeutics Research Centre, National Research Council of Canada, Ottawa, ON K1A 0R6, Canada"},{"name":"Faculty of Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,15]]},"reference":[{"key":"ref_1","first-page":"751","article-title":"Influenza: Diagnosis and Treatment","volume":"100","author":"Gaitonde","year":"2019","journal-title":"Am. 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