Seasonal vaccine-induced immunity shows preserved cross-reactivity to H3N2 subclade K in adults

medRxiv 2026 Preprint Open access

Read full text
Authors: Adria R. Wilson, Brian R Lerman, Reima Ramsamooj, Jacob Mischka, Jordan Ehrenhaus, Ashley Aracena, Yusuf Figueroa, Keith Farrugia, Ana Silvia Gonzalez-Reiche, Jessica Nardulli, Zain Khalil, Charles H. Gleason
+7 more Enikő Hermann, Komal Srivastava_, Emilia Mia Sordillo, Harm van Bakel, Anass Abbad, Florian Krammer, Viviana Simon
DOI: 10.64898/2026.02.18.26346502
Cited by: 1
References: 13

Abstract

Influenza A subclade K viruses caused high infection rates in the 2025/2026 Northern Hemisphere season, raising concerns about antigenic drift and reduced vaccine effectiveness. We measured antibody responses in matched human pre- and post-vaccination sera against a vaccine-like as well as subclade K isolates. Pre-existing immunity to subclade K variants was noted with seasonal influenza vaccination boosting titers two-fold against subclade K and three-fold against the vaccine-like strain, indicating little antigenic drift. These data contrast ferret-based predictions of marked antigenic drift.

Fields of Study & Subjects

Influenza Virus Research Studies HIV Research and Treatment Respiratory viral infections research

Publication details

Journal / source
medRxiv
Publisher
openRxiv
Publication date
18 February 2026
Language
EN
Document type
Preprint