TY - JOUR

T1 - H3N2 influenza virus characteristics in China (2019–2022): Genetic, antigenic, and infection dynamics during the COVID-19 pandemic

AU - Li, Jiaming

AU - Huan, Yu

AU - Xia, Qianfeng

AU - Li, Yan

AU - Khan, Rahat Ullah

AU - Liu, Qingzhi

AU - Dou, Chuanran

AU - Gulyaeva, Marina

AU - Shestopalov, Alexander

AU - Zhang, Ning

AU - Duan, Xuefeng

AU - Yang, Jing

AU - Zhang, Hongchun

AU - Bi, Yuhai

N1 - This work was supported by the National Key R&D Program of China (2022YFC3500804 and 2023YFC2307500 to Y.L. and Y.B.), the National Natural Science Foundation of China (NSFC) (32261133524 and 32425053 to Y.B.), the CAS Southeast Asia Biodiversity Research Institute (151C53KYSB20210023 to Y.B.), the Major Project of Guangzhou National Laboratory (GZNL2023A01001 to Y.B.), the National Science and Technology Infrastructure of China (National Pathogen Resource Center-NPRC-32 to Y.B.), the CAS Project for Young Scientists in Basic Research (YSBR-086 to Y.B.), the Youth Innovation Promotion Association of CAS (Y2021034 to Y.B.), the Innovation Team and Talents Cultivation Program of National Administration of Traditional Chinese Medicine (ZYYCXTD-D-202208 to Y.B.), and the Russian Science Foundation (23-44-00026 to M.G. and A.S.).

PY - 2025/2/11

Y1 - 2025/2/11

N2 - Seasonal influenza activity significantly decreased in China during the coronavirus disease 2019 (COVID-19) pandemic, yet the H3N2 virus led to three epidemic waves. Understanding the characteristics of H3N2 epidemic viruses is essential for recognizing influenza during COVID-19 and for updating vaccines. In this study, we analyzed 579 respiratory samples from patients exhibiting influenza-like symptoms, collected in 2019–2022, leading to the successful sequencing of 36 complete H3N2 genomes. Genomic analysis indicated that the epidemic strains from these periods belonged to different hemagglutinin (HA) clades and exhibited phylogenetic divergence from the concurrently used vaccine strains. Significant antigenic differences were identified through cross-hemagglutination inhibition (HI) and cross-microneutralization (MN) assays. Furthermore, pathogenicity studies showed that representative strains replicated in Madin-Darby canine kidney‌ (MDCK) cells, with varying abilities, and all replicated more effectively at 37 °C compared to 33 °C. These strains also replicated well in the respiratory tracts of mice and guinea pigs. The findings indicate a mismatch between circulating H3N2 viruses and recommended vaccine strains, highlighting the need for improved international cooperation and epidemiological surveillance of influenza viruses post-COVID-19. Optimizing effective vaccine strain update strategy and developing a universal influenza vaccine are crucial for future preparedness.

AB - Seasonal influenza activity significantly decreased in China during the coronavirus disease 2019 (COVID-19) pandemic, yet the H3N2 virus led to three epidemic waves. Understanding the characteristics of H3N2 epidemic viruses is essential for recognizing influenza during COVID-19 and for updating vaccines. In this study, we analyzed 579 respiratory samples from patients exhibiting influenza-like symptoms, collected in 2019–2022, leading to the successful sequencing of 36 complete H3N2 genomes. Genomic analysis indicated that the epidemic strains from these periods belonged to different hemagglutinin (HA) clades and exhibited phylogenetic divergence from the concurrently used vaccine strains. Significant antigenic differences were identified through cross-hemagglutination inhibition (HI) and cross-microneutralization (MN) assays. Furthermore, pathogenicity studies showed that representative strains replicated in Madin-Darby canine kidney‌ (MDCK) cells, with varying abilities, and all replicated more effectively at 37 °C compared to 33 °C. These strains also replicated well in the respiratory tracts of mice and guinea pigs. The findings indicate a mismatch between circulating H3N2 viruses and recommended vaccine strains, highlighting the need for improved international cooperation and epidemiological surveillance of influenza viruses post-COVID-19. Optimizing effective vaccine strain update strategy and developing a universal influenza vaccine are crucial for future preparedness.

KW - H3N2

KW - antigenicity

KW - genetic evolution

KW - infection

KW - influenza A virus

KW - phylogeny

UR - https://www.mendeley.com/catalogue/13990420-6f2b-385d-ba67-a1f619129f41/

UR - https://www.scopus.com/record/display.uri?eid=2-s2.0-85217947190&origin=inward&txGid=92f9e7ee0488559dc8536b4625319ebb

U2 - 10.1016/j.hlife.2025.01.004

DO - 10.1016/j.hlife.2025.01.004

M3 - Article

JO - hLife

JF - hLife

SN - 2949-9283

ER -