{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T11:24:19Z","timestamp":1787657059759,"version":"build-2736575974"},"reference-count":35,"publisher":"Wiley","issue":"8","license":[{"start":{"date-parts":[[2026,8,13]],"date-time":"2026-08-13T00:00:00Z","timestamp":1786579200000},"content-version":"vor","delay-in-days":12,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"},{"start":{"date-parts":[[2026,8,1]],"date-time":"2026-08-01T00:00:00Z","timestamp":1785542400000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/doi.wiley.com\/10.1002\/tdm_license_1.1"}],"funder":[{"DOI":"10.13039\/501100013302","name":"King Abdullah International Medical Research Center","doi-asserted-by":"publisher","award":["NRR26\/016\/1"],"award-info":[{"award-number":["NRR26\/016\/1"]}],"id":[{"id":"10.13039\/501100013302","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["onlinelibrary.wiley.com"],"crossmark-restriction":true},"short-container-title":["Journal of Medical Virology"],"published-print":{"date-parts":[[2026,8]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:p>\n                    The 2025\u20132026 Northern Hemisphere influenza season was characterised globally by rapid expansion of A(H3N2) subclade K. Saudi Arabia reported an A(H3N2)\u2010dominant epidemic peaking in epidemiological Weeks 43\u201346 (20 October\u201316 November 2025), with national test positivity reaching 36.8%. To characterise circulating H3N2 viruses and assess divergence from the vaccine reference strain, we performed amplicon\u2010based whole\u2010genome Oxford Nanopore sequencing of 149 residual A(H3N2)\u2010positive respiratory specimens collected in Riyadh between August and December 2025 (one specimen in August and the remainder during October\u2013December, reflecting the epidemic curve). We recovered 81 haemagglutinin (HA) and 71 neuraminidase (NA) high\u2010quality consensus sequences. Nextclade classified 64 HA sequences (79.0%) as subclade K and 17 (21.0%) as the parental clade J.2.4; NA sequences segregated into B.4.2.2 (61, 85.9%) and B.4.2 (10, 14.1%). Among 69 isolates with paired HA and NA, the two clade assignments were strongly non\u2010independent (Fisher exact two\u2010sided\n                    <jats:italic>p\u2009<\/jats:italic>\n                    =\u20098.4\u2009\u00d7\u200910\n                    <jats:sup>\u22124<\/jats:sup>\n                    ; odds ratio 0.077, 95% CI: 0.011\u20130.436), with the K\u2009+\u2009B.4.2.2 constellation predominating (50\/69, 72.5%). Twelve of 69 isolates (17.4%) showed an HA\u2013NA clade mismatch (nine J.2.4\u2010HA\u2009+\u2009B.4.2.2\u2010NA; three K\u2010HA\u2009+\u2009B.4.2\u2010NA), consistent with within\u2010season reassortment. Whole\u2010genome maximum\u2010likelihood phylogenies of all eight gene segments showed that the K and J.2.4 lineages remained largely coherent across the genome, with the internal segments broadly co\u2010segregating (pairwise topological concordance, Spearman\n                    <jats:italic>\u03c1<\/jats:italic>\n                    0.18\u20130.71); the reassortment signal was therefore concentrated at the HA\u2010NA surface\u2010gene pairing. Six HA1 substitutions (K2N, S144N, N158D, I160K, Q173R, T328A) discriminated subclade K from J.2.4 at high statistical significance and mapped to antigenic sites A, B, C, and D and the protein N\u2010terminus. No neuraminidase\u2010inhibitor or baloxavir resistance markers were detected. These data document a K\u2010clade\u2010predominant epidemic with persistent J.2.4 co\u2010circulation, within\u2010season HA\u2010NA reassortment, and marked HA1 divergence from the vaccine reference, against a background of fully susceptible antiviral genotypes.\n                  <\/jats:p>","DOI":"10.1002\/jmv.71102","type":"journal-article","created":{"date-parts":[[2026,8,13]],"date-time":"2026-08-13T09:15:19Z","timestamp":1786612519000},"update-policy":"https:\/\/doi.org\/10.1002\/crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Emergence and Genomic Characterisation of Influenza Virus A(H3N2) Subclade K in Saudi Arabia: Dominant Circulation With Fixed HA1 Substitutions and High\u2010Frequency HA\u2013NA Clade Association, 2025\u20132026"],"prefix":"10.1002","volume":"98","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2088-0629","authenticated-orcid":false,"given":"Asif","family":"Naeem","sequence":"first","affiliation":[{"name":"Infectious Diseases Research Department, King Abdullah International Medical Research Center (KAIMRC) King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs Riyadh Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0005-4403-9673","authenticated-orcid":false,"given":"Maymunah","family":"Hakami","sequence":"additional","affiliation":[{"name":"Infectious Diseases Research Department, King Abdullah International Medical Research Center (KAIMRC) King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs Riyadh Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0003-5518-0344","authenticated-orcid":false,"given":"Kadi Megbel","family":"Alanazi","sequence":"additional","affiliation":[{"name":"Infectious Diseases Research Department, King Abdullah International Medical Research Center (KAIMRC) King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs Riyadh Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1077-0872","authenticated-orcid":false,"given":"Nabeel","family":"Alzahrani","sequence":"additional","affiliation":[{"name":"Department of Clinical Laboratory Sciences, College of Applied Medical Sciences King Saud Bin Abdulaziz University for Health Sciences Riyadh Saudi Arabia"},{"name":"Division of Microbiology, Department of Pathology and Laboratory Medicine Ministry of the National Guard Health Affairs Riyadh Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mohammad","family":"Bosaeed","sequence":"additional","affiliation":[{"name":"Infectious Diseases Research Department, King Abdullah International Medical Research Center (KAIMRC) King Saud bin Abdulaziz University for Health Sciences, Ministry of National Guard Health Affairs Riyadh Saudi Arabia"},{"name":"College of Medicine King Saud Bin Abdulaziz University for Health Sciences Riyadh Saudi Arabia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2026,8,13]]},"reference":[{"key":"e_1_2_11_2_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(17)33293-2"},{"key":"e_1_2_11_3_1","doi-asserted-by":"publisher","DOI":"10.1126\/science.1097211"},{"key":"e_1_2_11_4_1","doi-asserted-by":"publisher","DOI":"10.7554\/eLife.01914"},{"key":"e_1_2_11_5_1","doi-asserted-by":"publisher","DOI":"10.1093\/bioinformatics\/bty407"},{"key":"e_1_2_11_6_1","doi-asserted-by":"publisher","DOI":"10.21105\/joss.03773"},{"key":"e_1_2_11_7_1","volume-title":"Threat Assessment Brief: Assessing the Risk of Influenza for the EU\/EEA in the Context of Increasing Circulation of A(H3N2) Subclade K","author":"European Centre for Disease Prevention and Control","year":"2025"},{"key":"e_1_2_11_8_1","unstructured":"Centers for Disease Control and Prevention. 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