The hemagglutinin (HA) of A/H3N2 pandemic influenza viruses (IAVs) of 1968 differed from its inferred avian precursor by eight amino acid substitutions. To determine their phenotypic effects, we studied recombinant variants of A/Hong Kong/1/1968 virus containing either human-type or avian-type amino acids in the corresponding positions of HA. The precursor HA displayed receptor binding profile and high conformational stability typical for duck IAVs. Substitutions Q226L and G228S, in addition to their known effects on receptor specificity and replication, marginally decreased HA stability. Substitutions R62I, D63N, D81N and N193S reduced HA binding avidity. Substitutions R62I, D81N and A144G promoted viral replication in human airway epithelial cultures. Analysis of HA sequences revealed that substitutions D63N and D81N accompanied by the addition of N-glycans represent common markers of avian H3 HA adaptation to mammals. Our results advance understanding of genotypic and phenotypic changes in IAV HA required for avian-to-human adaptation and pandemic emergence.
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http://dx.doi.org/10.1371/journal.ppat.1009566 | DOI Listing |
Hum Vaccin Immunother
December 2025
Centre for Health Behavious Research, Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong, China.
People's risk of contracting seasonal influenza increased after COVID-19 control measures were relaxed. This study investigated the changes in seasonal influenza vaccination (SIV) uptake and its determinants among older adults during and after the COVID-19 period. Two rounds of random telephone surveys were conducted among 440 and 373 community-living individuals aged ≥65 y, the first between November 2021 and January 2022 and the second between October 2023 and January 2024.
View Article and Find Full Text PDFBMC Public Health
January 2025
International Healthcare Center, Seoul National University Hospital, Seoul, Korea.
Background: This study aimed to investigate the sociodemographic and behavioral factors related to increased influenza vaccination uptake during the COVID-19 pandemic in South Korea, particularly among adults not eligible for free vaccination.
Methods: Analyzing data from 78,815 participants in the Korea National Health and Nutrition Examination Survey (2010-2021), we assessed trends in influenza vaccination coverage. Various sociodemographic factors, behavioral aspects, and psychological stress levels were assessed using multivariable logistic regression to evaluate the difference in vaccination response during pre-/post-COVID-19 periods.
Arch Virol
January 2025
CAS Key Laboratory of Molecular Virology & Immunology, Institutional Center for Shared Technologies and Facilities, Pathogen Discovery and Big Data Platform, Shanghai Institute of Immunity and Infection, Chinese Academy of Sciences, Yueyang Road 320, Shanghai, 200031, China.
To battle seasonal outbreaks of influenza B virus infection, which continue to pose a major threat to world health, new and improved vaccines are urgently needed. In this article, we discuss the current state of next-generation influenza B vaccine development, including both advancements and challenges. This review covers the shortcomings of existing influenza vaccines and stresses the need for more-effective and broadly protective vaccines and more-easily scalable manufacturing processes.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Clinical Laboratory Medicine, Kyoto University Graduate School of Medicine, Kyoto, Japan.
The seasonality and epidemiology of viral acute respiratory infections (ARIs) have changed since the coronavirus disease 2019 pandemic. However, molecular-based ARI surveillance has not been conducted in Japan. We developed a regional surveillance program to define the local epidemiology of ARIs.
View Article and Find Full Text PDFJ Med Internet Res
January 2025
College of Nursing Science, Kyung Hee University, Seoul, Republic of Korea.
Background: Emerging infectious disease disasters receive extensive media coverage and public attention. Nurse burnout and attrition peak during health crises such as pandemics. However, there is limited research on nursing issues related to repeated emerging infectious disease crises over time.
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