{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T06:22:42Z","timestamp":1787638962251,"version":"build-2736575974"},"reference-count":39,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T00:00:00Z","timestamp":1787616000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Immunol."],"abstract":"<jats:p>SARS-CoV-2 Omicron evolution continues to erode antibody-mediated immunity, but whether infection with antigenically distinct lineages simply amplifies pre-existing memory or redirects humoral recognition toward newly evolved antigenic space remains unclear. Here, we analyzed paired early- and convalescent-phase plasma and whole-blood samples from individuals with sequencing-confirmed BF.7 or JN.1 infection. Integrated neutralization profiling, antigenic cartography, and bulk B cell receptor (BCR) repertoire analysis revealed lineage-associated humoral trajectories. Both breakthrough infections increased cross-variant neutralization, but their updated humoral profiles were not equivalent. BF.7 breakthrough infection broadly boosted neutralization from a BA.5-related background, whereas JN.1 breakthrough infection produced greater gains against BA.2.86, JN.1, and KP.2 and shifted humoral recognition toward late-Omicron antigenic space. Neutralization remained branch-structured, with BQ.1.1 and KP.2 acting as persistent escape nodes within the BA.2\/BA.5-related and BA.2.86\/JN.1-related branches, respectively. This humoral updating paralleled changes in IGH clonotype counts, repertoire diversity, V\/J gene usage, isotype composition, and V\u2013J pairing, whereas major CDR3 length distributions and sequence-logo patterns remained largely conserved. Overall, these findings indicate that antigenically distinct Omicron breakthrough infections generate non-equivalent humoral recall trajectories: BF.7 exposure preferentially reinforced BA.5-related antibody recognition, whereas JN.1 exposure more effectively redirected recognition toward BA.2.86\/JN.1-derived variants.<\/jats:p>","DOI":"10.3389\/fimmu.2026.1906350","type":"journal-article","created":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T05:35:36Z","timestamp":1787636136000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Comparative analysis of immune escape and BCR repertoire remodeling after Omicron BF.7 and JN.1 infections"],"prefix":"10.3389","volume":"17","author":[{"given":"Luanfeng","family":"Lin","sequence":"first","affiliation":[{"name":"The First Clinical College of Fujian Medical University, the First Affiliated Hospital of Fujian Medical University","place":["Fuzhou, 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Hospital, Fudan University","place":["Shanghai, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xinyi","family":"Yu","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University","place":["Shanghai, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Tianmei","family":"Yu","sequence":"additional","affiliation":[{"name":"Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University","place":["Shanghai, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiaoyu","family":"Zhao","sequence":"additional","affiliation":[{"name":"Shanghai Sci-Tech Inno Center for Infection & Immunity, National Medical Center 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China"]},{"name":"Department of Infectious Diseases, Shanghai Key Laboratory of Infectious Diseases and Biosafety Emergency Response, National Medical Center for Infectious Diseases, Huashan Hospital, Fudan University","place":["Shanghai, China"]},{"name":"Department of Infection Medicine Center, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University","place":["Fuzhou, China"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,8,25]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1038\/s41586-024-08315-x","article-title":"Evolving antibody response to SARS-CoV-2 antigenic shift from XBB to JN.1","volume":"637","author":"Jian","year":"2025","journal-title":"Nature"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(23)01367-3","article-title":"Omicron neutralisation: RBD-dimer booster versus BF.7 and BA.5.2 breakthrough 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