Risk Factors for Failure to Respond to Influenza Vaccination Among Adults Hospitalized with Community-Acquired Pneumonia in the CDCE tiology of Pneumonia in the Community (EPIC) Study Open Access

Pratt, Caroline Quinn (2016)

Permanent URL: https://etd.library.emory.edu/concern/etds/vm40xr78m?locale=en


Background: Despite influenza vaccination recommendations for adults, many remain unvaccinated. Strategies to improve influenza vaccination are needed. Administration of influenza vaccine during non-influenza associated hospital admissions may improve influenza vaccination rates, but the serological response to vaccination might be impaired due to illness.

Methods: Adults with radiologically-confirmed pneumonia requiring hospitalization were prospectively enrolled into the CDC-sponsored Etiology of Pneumonia in the Community (EPIC) study. A subset of these enrolled adults without evidence of influenza infection received seasonal influenza vaccination in between the obtaining of acute and convalescent serologies. Seroconversion was defined as those with ≥4-fold rise in hemagglutination inhibition (HAI) titer between acute and convalescent serology for influenza A (H3N2 or H1N1) and/or B (Yamagata or Victoria strain). Risk factors associated with failure to seroconvert to influenza vaccination were identified. Multivariate stepwise analysis was conducted using variables potentially associated with failure to seroconvert identified on univariate analysis (p<0.20).

Results: Of the 95 patients meeting the inclusion criteria, 66 (69.5%) seroconverted to one or more strains of influenza. In univariate analysis, failure to seroconvert was associated with diabetes (p=0.03) and an elevated baseline HAI titer for influenza B (Yamagata) strain (p=0.03). Other variables approaching significance included in the stepwise multivariate model were gender (p=0.15), receipt of influenza vaccine in prior season (p=0.05), liver disease (p=0.07), identification of a bacterial pathogen (p=0.09), and elevated baseline HAI titer for influenza A (H3N2) (p=0.17). Markers of CAP severity did not correlate with failure to seroconvert. On multivariate analysis, failure to seroconvert was predicted by diabetes (p=0.02), receipt of the influenza vaccine in the previous season (p=0.03), presence of bacterial pathogen (p=0.05), and elevated influenza B (Yamagata) HAI titer at baseline (p=0.03). It inversely correlated with the presence of liver disease (p=0.05).

Conclusions: One-third of patients who received seasonal influenza vaccination during hospitalization for community-acquired pneumonia did not seroconvert. Failure to seroconvert was associated with diabetes, receipt of influenza vaccine in the prior season, presence of bacterial infection, and elevated influenza B HAI baseline titers. Certain groups may be at risk for failure to seroconvert after receiving seasonal influenza vaccine while hospitalized for CAP.

Table of Contents

Abstract 5

Chapter I: Background 8

Influenza and Vaccination 8

Past Studies 9

Description of Dataset 9

Hypothesis 10

Outcome of Interest 11

Variables of Interest 12

Chapter II: Manuscript 15

Title 15

Abstract 15

Introduction 18

Methods 20

Patient Population 20

Study Design 20

Statistical Methods 21

Results 23

Subject Distributions 23

Univariate Analysis 23

Multivariate Analysis 24

Discussion 26

Manuscript References 31

Tables 34

Figures 38

Chapter III: Summary 39

Additional Tables 43

References (Excludes Manuscript References) 44

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