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Updated: Jun 3, 2025
An Optimized Hemagglutination Inhibition HI Assay to Quantify Influenza-specific Antibody Titers
Published on: December 1, 2017
High-Dose Inactivated Influenza Vaccine Inconsistently Improves Heterologous Antibody Responses in an Older Human
W Zane Billings1,2, Yang Ge1, Jessica H Knight1
1Department of Epidemiology and Biostatistics, College of Public Health, University of Georgia, Athens, Georgia.
Background:
Older adults often mount a weak immune response to standard inactivated influenza vaccines. To induce a stronger response and better protection, a high-dose (HD) version of the inactivated Fluzone vaccine is recommended for individuals >65 years of age. While better immunogenicity and protection against the vaccine strain have been shown, it is not known if the HD vaccine also induces a robust antibody response to heterologous strains.
Methods:
We fit bayesian multilevel regression models to hemagglutination inhibition antibody data from an influenza vaccine cohort spanning the influenza seasons of 2013-2014 to 2021-2022. We used this model to estimate the average causal effect of obtaining the HD vaccine relative to the standard-dose vaccine.
Results:
We show that while there is generally a benefit derived from the HD vaccine, the impact is small and inconsistent. For some strains, the HD vaccine might even result in less robust heterologous responses.
Conclusions:
We suggest that further increases in dose might be worth investigating to help induce a stronger broad response.
