{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,26]],"date-time":"2026-03-26T14:55:11Z","timestamp":1774536911910,"version":"3.50.1"},"reference-count":32,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,3,26]],"date-time":"2026-03-26T00:00:00Z","timestamp":1774483200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Secihti","award":["CBF-2025-G-1850"],"award-info":[{"award-number":["CBF-2025-G-1850"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pathogens"],"abstract":"<jats:p>Influenza A viruses (IAVs) are among the most common sources of new pandemic strains in humans. Spillover from birds to mammals can lead to viral adaptation in new hosts, as seen with IAV H5N1. H5N2 viruses have also been transmitted successfully to humans through contact with infected birds and poultry. In the present study, we evaluated the presence of antibodies against H5Nx viruses in serum samples from a Mexican adult population (n = 476) using the hemagglutination inhibition (HI) test. The analysis included comparisons between sex and age groups. Potential epitopes recognized in the H5 proteins of each strain were predicted using Ellipro. We detected antibodies against H5N1 in 2.5% of the samples, with the highest HI titers of 1:64. The proportion of positive samples for H5N2 2006 was higher (18.9%) than for H5N2 2024 (10.7%). The oldest groups (&gt;50 years old) showed the highest proportion of positives for both viruses, whereas the youngest was for H5N1. These results demonstrate a low proportion of cross-reactive antibodies against the IAV H5N1.<\/jats:p>","DOI":"10.3390\/pathogens15040352","type":"journal-article","created":{"date-parts":[[2026,3,26]],"date-time":"2026-03-26T13:36:40Z","timestamp":1774532200000},"page":"352","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Antibody Recognition of Highly and Low-Pathogenic A\/H5Nx Influenza Viruses in Sera of Mexican Donors"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0004-2702-5299","authenticated-orcid":false,"given":"Maritza","family":"Cordero-Ortiz","sequence":"first","affiliation":[{"name":"Laboratorio de Inmunolog\u00eda, Centro de Investigaci\u00f3n en Alimentaci\u00f3n y Desarrollo, Hermosillo 83148, Sonora, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-7285-9396","authenticated-orcid":false,"given":"Mario","family":"Sol\u00eds-Hern\u00e1ndez","sequence":"additional","affiliation":[{"name":"Comisi\u00f3n M\u00e9xico-Estados Unidos para la Prevenci\u00f3n de la Fiebre Aftosa y otras Enfermedades Ex\u00f3ticas de los Animales (CPA), Servicio Nacional de Sanidad, Inocuidad y Calidad Agroalimentaria (SENASICA), Secretar\u00eda de Agricultura y Desarrollo Rural (SADER), Ciudad de M\u00e9xico 05110, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Marlen","family":"Cayetano-Mondrag\u00f3n","sequence":"additional","affiliation":[{"name":"Comisi\u00f3n M\u00e9xico-Estados Unidos para la Prevenci\u00f3n de la Fiebre Aftosa y otras Enfermedades Ex\u00f3ticas de los Animales (CPA), Servicio Nacional de Sanidad, Inocuidad y Calidad Agroalimentaria (SENASICA), Secretar\u00eda de Agricultura y Desarrollo Rural (SADER), Ciudad de M\u00e9xico 05110, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nadia Carrillo","family":"Guzm\u00e1n","sequence":"additional","affiliation":[{"name":"Comisi\u00f3n M\u00e9xico-Estados Unidos para la Prevenci\u00f3n de la Fiebre Aftosa y otras Enfermedades Ex\u00f3ticas de los Animales (CPA), Servicio Nacional de Sanidad, Inocuidad y Calidad Agroalimentaria (SENASICA), Secretar\u00eda de Agricultura y Desarrollo Rural (SADER), Ciudad de M\u00e9xico 05110, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4456-2107","authenticated-orcid":false,"given":"Olivia","family":"Valenzuela","sequence":"additional","affiliation":[{"name":"Departamento de Ciencias Qu\u00edmico Biol\u00f3gicas, Divisi\u00f3n de Ciencias de la Salud, Universidad de Sonora, Hermosillo 83000, Sonora, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7394-4569","authenticated-orcid":false,"given":"Ver\u00f3nica","family":"Mata-Haro","sequence":"additional","affiliation":[{"name":"Laboratorio de Microbiolog\u00eda e Inmunolog\u00eda, Centro de Investigaci\u00f3n en Alimentaci\u00f3n y Desarrollo, Hermosillo 83304, Sonora, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4407-7996","authenticated-orcid":false,"given":"Luis G.","family":"Gim\u00e9nez-Lirola","sequence":"additional","affiliation":[{"name":"College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5131-3600","authenticated-orcid":false,"given":"Jes\u00fas","family":"Hern\u00e1ndez","sequence":"additional","affiliation":[{"name":"Laboratorio de Inmunolog\u00eda, Centro de Investigaci\u00f3n en Alimentaci\u00f3n y Desarrollo, Hermosillo 83148, Sonora, Mexico"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,26]]},"reference":[{"key":"ref_1","unstructured":"ICTV (2026, March 03). ICTV Taxonomy Browser. Taxon Details. Available online: https:\/\/ictv.global\/taxonomy\/taxondetails?taxnode_id=202403956&ictv_id=ICTV19710226."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"e00020","DOI":"10.1128\/msphere.00020-25","article-title":"Virus species names have been standardized; virus names remain unchanged","volume":"10","author":"Zerbini","year":"2025","journal-title":"mSphere"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"304","DOI":"10.1038\/s41586-024-08054-z","article-title":"The global H5N1 influenza panzootic in mammals","volume":"637","author":"Peacock","year":"2025","journal-title":"Nature"},{"key":"ref_4","unstructured":"World Animal Health Information System Interface (2024, May 20). Mexico-High Pathogenicity Avian Influenza Viruses (Poultry) (Inf. with)-Follow up Report 6 [FINAL]. Available online: https:\/\/wahis.woah.org\/#\/in-review\/4762?reportId=163107&fromPage=event-dashboard-url."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1335","DOI":"10.3201\/eid3007.240508","article-title":"Highly Pathogenic Avian Influenza A(H5N1) Clade 2.3.4.4b Virus Infection in Domestic Dairy Cattle and Cats, United States, 2024","volume":"30","author":"Burrough","year":"2024","journal-title":"Emerg. Infect. Dis. J."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"2515135518821625","DOI":"10.1177\/2515135518821625","article-title":"A review of H5Nx avian influenza viruses","volume":"7","author":"Ross","year":"2019","journal-title":"Ther. Adv. Vaccines Immunother."},{"key":"ref_7","first-page":"e8930","article-title":"Avian influenza overview March\u2013June 2024","volume":"22","author":"Alexakis","year":"2024","journal-title":"EFSA J."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"V\u00e1zquez-P\u00e9rez, J.A., Wong-Ar\u00e1mbula, C., Sol\u00eds-Hern\u00e1ndez, M., Becerril-Vargas, E., Barrera-Badillo, G., Ahumada-Topete, V.H., Avila-Rios, S., P\u00e9rez-Padilla, R., Mej\u00eda-Nepomuceno, F., and Mendoza-Ram\u00edrez, E. (2025). Mexico\u2019s Laboratory-Confirmed Human Case of Infection with the Influenza A(H5N2) Virus. Viruses, 17.","DOI":"10.3390\/v17020205"},{"key":"ref_9","first-page":"413","article-title":"First confirmed human case of H5N2 virus infection in Mexico: An emerging zoonotic concern","volume":"32","author":"Apostolopoulos","year":"2024","journal-title":"Le Infez. Med."},{"key":"ref_10","doi-asserted-by":"crossref","unstructured":"V\u00e1zquez-P\u00e9rez, J.A., Becerril-Vargas, E., Ram\u00edrez-Gonz\u00e1lez, J.E., Sol\u00eds-Hern\u00e1ndez, M., Davis, C.T., Garciadiego-Fossas, P., Villanueva-Reza, M., Ch\u00e1vez-Morales, H.H., Mendoza-Ram\u00edrez, E., and Olivares-Flores, C.D. (2025). Emergence of a novel reassorted high pathogenicity avian influenza A(H5N2) virus associated with severe pneumonia in a young adult. medRxiv, medRxiv:2025.11.21.25340167.","DOI":"10.1101\/2025.11.21.25340167"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2400020","DOI":"10.2807\/1560-7917.ES.2024.29.39.2400020","article-title":"Co-circulation of seasonal influenza A(H1N1)pdm09, A(H3N2) and B\/Victoria lineage viruses with further genetic diversification, EU\/EEA, 2022\/23 influenza season","volume":"29","author":"Broberg","year":"2024","journal-title":"Euro Surveill."},{"key":"ref_12","unstructured":"World Health Organization (2025, September 03). Influenza (Seasonal). Available online: https:\/\/www.who.int\/news-room\/fact-sheets\/detail\/influenza-(seasonal)."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"eadw4856","DOI":"10.1126\/scitranslmed.adw4856","article-title":"Preexisting immunity to the 2009 pandemic H1N1 virus reduces susceptibility to H5N1 infection and disease in ferrets","volume":"17","author":"Restori","year":"2025","journal-title":"Sci. Transl. Med."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1454","DOI":"10.1038\/s41591-025-03599-6","article-title":"Immune history shapes human antibody responses to H5N1 influenza viruses","volume":"31","author":"Garretson","year":"2025","journal-title":"Nat. Med."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"174","DOI":"10.1038\/s41392-023-01447-y","article-title":"Neutralization of Omicron BA.1, BA.5.1.6, BQ.1.3 and XBB1.1 induced by heterologous vaccination Ad5-nCoV and mRNA-1273","volume":"8","author":"Valenzuela","year":"2023","journal-title":"Signal Transduct. Target. Ther."},{"key":"ref_16","first-page":"e734","article-title":"Analysis of IgG, IgA and IgM antibodies against SARS-CoV-2 spike protein S1 in convalescent and vaccinated patients with the Pfizer-BioNTech and CanSinoBio vaccines","volume":"69","author":"Valenzuela","year":"2022","journal-title":"Transbound. Emerg. Dis."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"100709","DOI":"10.1016\/j.jvacx.2025.100709","article-title":"H5N1 highly pathogenic avian influenza vaccination: Seroresponse of mexican poultry in the 2022\u20132024","volume":"26","author":"Badillo","year":"2025","journal-title":"Vaccine X"},{"key":"ref_18","unstructured":"World Health Organization (2002). WHO Manual on Animal Influenza Diagnosis and Surveillance, World Health Organization."},{"key":"ref_19","unstructured":"World Organisation for Animal Health (2026, March 03). Avian Influenza (Infection with Avian Influenza Viruses). Available online: https:\/\/www.woah.org\/es\/que-hacemos\/normas\/codigos-y-manuales\/#chapter\/?rid=335&volume_no=3&ismanual=true&language=104&standard_type=6&animal_type=7."},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Possas, C., Marques, E.T.A., Oliveira, A., Schumacher, S., Siqueira, M.M., McCauley, J., Antunes, A., and Homma, A. (2025). Highly pathogenic avian influenza: Pandemic preparedness for a scenario of high lethality with no vaccines. Front. Public Health, 13.","DOI":"10.3389\/fpubh.2025.1613869"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"e00424","DOI":"10.1128\/jvi.00424-25","article-title":"Clade 2.3.4.4b highly pathogenic avian influenza H5N1 viruses: Knowns, unknowns, and challenges","volume":"99","author":"Xie","year":"2025","journal-title":"J. Virol."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"494","DOI":"10.1016\/j.immuni.2025.12.013","article-title":"Pre-existing neutralizing antibodies against cattle-transmitted influenza A virus H5N1 are detectable in unexposed individuals","volume":"59","author":"Daniel","year":"2026","journal-title":"Immunity"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"10","DOI":"10.1128\/JCM.00750-20","article-title":"Comparability of Titers of Antibodies against Seasonal Influenza Virus Strains as Determined by Hemagglutination Inhibition and Microneutralization Assays","volume":"58","author":"Heeringa","year":"2020","journal-title":"J. Clin. Microbiol."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"6777","DOI":"10.1016\/j.vaccine.2009.08.056","article-title":"Measurement of neutralizing antibody responses against H5N1 clades in immunized mice and ferrets using pseudotypes expressing influenza hemagglutinin and neuraminidase","volume":"27","author":"Tsai","year":"2009","journal-title":"Vaccine"},{"key":"ref_25","first-page":"e03721","article-title":"Are we serologically prepared against an avian influenza pandemic and could seasonal flu vaccines help us?","volume":"16","author":"Mostafa","year":"2024","journal-title":"mBio"},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"de Bruin, A.C.M., Funk, M., Spronken, M.I., Gultyaev, A.P., Fouchier, R.A.M., and Richard, M. (2022). Hemagglutinin Subtype Specificity and Mechanisms of Highly Pathogenic Avian Influenza Virus Genesis. Viruses, 14.","DOI":"10.3390\/v14071566"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"9954","DOI":"10.1128\/JVI.78.18.9954-9964.2004","article-title":"Molecular Determinants within the Surface Proteins Involved in the Pathogenicity of H5N1 Influenza Viruses in Chickens","volume":"78","year":"2004","journal-title":"J. Virol."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1080\/22221751.2019.1708215","article-title":"Contribution of Fc-dependent cell-mediated activity of a vestigial esterase-targeting antibody against H5N6 virus infection","volume":"9","author":"Zheng","year":"2020","journal-title":"Emerg. Microbes Infect."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1329","DOI":"10.1093\/infdis\/jiae241","article-title":"Hemagglutinin Stalk-Specific Fc-Mediated Functions Are Associated with Protection Against Influenza Illness After Seasonal Influenza Vaccination","volume":"230","author":"Motsoeneng","year":"2024","journal-title":"J. Infect. Dis."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"105785","DOI":"10.1016\/j.antiviral.2023.105785","article-title":"Broadly neutralizing antibodies to combat influenza virus infection","volume":"221","author":"Sun","year":"2024","journal-title":"Antivir. Res."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"EFSA Panel on Animal Health and Animal Welfare (AHAW), ECDC, \u00c1lvarez, J., Boklund, A., Dippel, S., D\u00f3rea, F., Figuerola, J., Herskin, M., Michel, V., and Chueca, M.M. (2025). Preparedness, prevention and control related to zoonotic avian influenza. EFSA J., 23, e9191.","DOI":"10.2903\/j.efsa.2025.9191"},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Chen, X., Wang, W., Wang, Y., Lai, S., Yang, J., Cowling, B.J., Horby, P.W., Uyeki, T.M., and Yu, H. (2020). Serological evidence of human infections with highly pathogenic avian influenza A(H5N1) virus: A systematic review and meta-analysis. BMC Med., 18.","DOI":"10.1186\/s12916-020-01836-y"}],"container-title":["Pathogens"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-0817\/15\/4\/352\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,3,26]],"date-time":"2026-03-26T14:01:11Z","timestamp":1774533671000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-0817\/15\/4\/352"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,3,26]]},"references-count":32,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2026,4]]}},"alternative-id":["pathogens15040352"],"URL":"https:\/\/doi.org\/10.3390\/pathogens15040352","relation":{},"ISSN":["2076-0817"],"issn-type":[{"value":"2076-0817","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,3,26]]}}}