Background: High-dose trivalent influenza vaccine was developed to improve antibody responses to influenza vaccine in the elderly and hence potentially impact favorably on influenza-associated morbidity and mortality in this population.
Methods: A phase IIIb, multicenter, randomized, double-blind, controlled trial was conducted to compare High-Dose (HD) trivalent inactivated influenza vaccine (60μg of hemagglutinin [HA] per strain) to standard dose (SD) vaccine (15μg of HA per strain) in adults ≥65 years of age. Assessments of safety (serious adverse events [SAE]), immunogenicity (hemagglutination inhibition [HAI] titers) and relative efficacy were performed during the 2009-2010 influenza season, which coincided with the H1N1 pandemic.
Results: A total of 9172 participants were enrolled in 99 research centers in the US (6117 and 3055 randomized to the HD and SD groups, respectively). Within 180 days after vaccination, 6.7% and 6.5% of participants in the HD and SD vaccine groups, respectively, experienced at least one SAE, of which 0.4% and 0.3% had a fatal outcome. A total of 0.5% of participants in both groups discontinued the study due to a SAE. Post-vaccination HAI titers and rate of post-vaccination HAI titer ≥1:40 were significantly higher in the HD group. No cases of influenza caused by viral types/subtypes similar to those in the vaccines were observed. All cases genetically or antigenically characterized were classified as similar to influenza A/California/7/2009 (H1N1), the pandemic strain. The vaccine efficacy of HD vaccine relative to SD vaccine against any influenza viral type/subtype was 12.6% (95% CI -140.5; 65.8) in the intent-to-treat analysis.
Conclusion: High-dose trivalent inactivated influenza vaccine is safe and well tolerated and provides superior immune responses compared to standard dose vaccine. Demonstration of a superior vaccine efficacy requires a separate large randomized, controlled trial.
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http://dx.doi.org/10.1016/j.vaccine.2012.12.013 | DOI Listing |
Cell Host Microbe
December 2024
Zhejiang Key Laboratory of Multi-Omics in Infection and Immunity, Center for Infectious Disease Research, School of Medicine, Westlake University, Hangzhou, Zhejiang, China; Research Center for Industries of the Future, Westlake University, Hangzhou, Zhejiang, China; School of Life Science, Westlake University, Hangzhou, Zhejiang, China. Electronic address:
Identifying broadly reactive B precursor cells and conserved epitopes is crucial for developing a universal flu vaccine. In this study, using influenza neuraminidase (NA) mutant probes, we find that human pre-existing NA-specific memory B cells (MBCs) account for ∼0.25% of total MBCs, which are heterogeneous and dominated by class-unswitched MBCs.
View Article and Find Full Text PDFVaccine
December 2024
Department of Public Health, Faculty of Medicine, University of Helsinki, Finland.
In Finland, trust in science and research organisations is high. This correlates with the fact that childhood vaccination uptake is generally good in Finland, with vaccine refusal being rare. However, there are differences between vaccines and regions in terms of uptake.
View Article and Find Full Text PDFVaccine
December 2024
Department of Microbiology and Immunology, University of Melbourne, at The Peter Doherty Institute for Infection and Immunity, Melbourne, Victoria 3000, Australia. Electronic address:
Recombinant influenza viruses are promising vectors that can bolster antibody and resident lymphocyte responses within mucosal sites. This study evaluates recombinant influenza viruses with SARS-CoV-2 RBD genes in eliciting mucosal and systemic responses. Using reverse genetics, we generated replication-competent recombinant influenza viruses carrying heterologous RBD genes in monomeric, trimeric, or ferritin-based nanoparticle forms.
View Article and Find Full Text PDFPLoS One
December 2024
Mel and Enid Zuckerman College of Public Health, University of Arizona, Tucson, Arizona, United States of America.
The extent to which semi-quantitative antibody levels confer protection against SARS-CoV-2 infection in populations with heterogenous immune histories is unclear. Two nested case-control studies were designed within the multisite HEROES/RECOVER prospective cohort of frontline workers to study the relationship between antibody levels and protection against first-time post-vaccination infection and reinfection with SARS-CoV-2 from December 2021 to January 2023. All participants submitted weekly nasal swabs for rRT-PCR testing and blood samples quarterly and following infection or vaccination.
View Article and Find Full Text PDFPLoS One
December 2024
Institute of Industrial Science, The University of Tokyo, Bunkyo-ku, Tokyo, Japan.
To prevent widespread epidemics such as influenza or measles, it is crucial to reach a broad acceptance of vaccinations while addressing vaccine hesitancy and refusal. To gain a deeper understanding of Japan's sharp increase in COVID-19 vaccination coverage, we performed an analysis on the posts of Twitter users to investigate the formation of users' stances toward COVID-19 vaccines and information-sharing actions through the formation. We constructed a dataset of all Japanese posts mentioning vaccines for five months since the beginning of the vaccination campaign in Japan and carried out a stance detection task for all the users who wrote the posts by training an original deep neural network.
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