Introduction: Seasonal influenza B is an important contributor to the overall burden of influenza during each season. There is recent evidence of lower vaccine effectiveness (VE) against influenza A for those vaccinated in prior seasons. However, this relationship has not yet been investigated for influenza B.
Methods: Hemagglutination inhibition antibody (HI) assays were collected preseason and ~30 days post-vaccination from a prospective healthcare personnel (HCP) cohort. Eligible participants had confirmed medical and vaccination records for four years and received the 2010-11 trivalent inactivated influenza vaccine (IIV3) containing B/Brisbane/60/2008-like virus (B/Victoria). Preseason and post-vaccination geometric mean titers (GMTs), geometric mean ratio (GMR), and fold-change were assessed for B/Brisbane/60/2008 (B/Victoria), B/Florida/4/2006 (B/Yamagata), and B/Malaysia/2506/2004 (B/Victoria) response adjusted for age, sex, race, education, household size and hospital care responsibilities.
Results: All three viruses had post-vaccination fold change results inversely associated with the number of prior vaccinations and only B/Florida experienced a significant, direct, association for preseason GMT. B/Brisbane and B/Malaysia experienced a significant increase in adjusted GMR among those with no prior vaccinations (GMR = 1.61 and 1.42, respectively) compared to having received at least one prior vaccination. B/Florida exhibited a similar increase in adjusted GMR for no prior vaccinations (GMR = 1.18) and was significantly higher than HCP that received 2-4 prior vaccinations.
Conclusions: Our findings suggest that a single prior IIV3 vaccination reduces immune response and cross-reactivity of influenza B virus with non-significant differences between one and four prior vaccination responses. Ultimately, more research into specific B vaccine component response and cross-reactivity to other B viruses may be needed to optimize immunogenicity and vaccine effectiveness among HCP and other repeated vaccinees.
Table of Contents
Table of Contents
Chapter I: Background and Literature Review.. 1
Burden of Disease. 1
Immunization Practice. 5
Chapter II: Manuscript 8
Title, Authors, Abstract 8
Chapter III: Extended Discussion. 38
Public Health Implications. 38
Possible Future Directions. 39
About this Master's Thesis
|Committee Chair / Thesis Advisor|