538. Effect of Body Mass Index on Serologic Response to Influenza Vaccination in Older Adults
Session: Poster Abstract Session: Influenza Vaccines
Friday, October 21, 2011
Room: Poster Hall B1
  • 11_0926 IDSA538.pdf (662.1 kB)
  • Background: Obesity is associated with impaired immunity; interest in this issue increased when extreme obesity was identified as an independent risk factor for hospitalization and death due to 2009 pandemic H1N1 influenza.  We sought to determine if body mass index (BMI) independently predicts serologic response to influenza vaccination in older adults. 

    Methods: Adults ≥ 50 yrs were recruited from 2 communities in WI and TN during the 2008-09 influenza season.  415 subjects provided pre- and post-vaccination sera for measurement of hemagglutination inhibition assay (HI) antibody titers; height and weight were measured.  Titers to 2008-09 vaccine components A/Brisbane/59/2007 (H1N1), A/Brisbane 10/2007 (H3N2), and B/Florida/4/2006 were measured; seroprotection was defined as titer ≥ 40 and seroconversion as ≥ 4-fold increase in post-vaccination titer. BMI was calculated as weight (kg) ÷ height (m)2.  Logistic regression models evaluated the association between BMI and seroprotection or seroconversion, adjusting for gender, age, comorbidities, and pre-vaccination HI titer.

    Results: Mean (± standard deviation) age of subjects was 65 ± 10 yrs; 60% were female and 16% reported ≥ 1 comorbid condition.  Mean BMI was 29 ± 5.6 kg/m2.   The proportions of subjects who seroconverted and had seroprotective titers were 40% and 49%, respectively, for A/Brisbane/59; 73% and 80% for A/Brisbane/10; and 34% and 94% for B/Florida. In logistic regression models, BMI did not predict seroprotection:  odds ratio [95% confidence interval] 0.84 [0.55, 1.29] and 1.32 [0.80, 2.17] for H1N1 and H3N2 subtypes, respectively. Seroprotection against influenza B was not modeled due to the high proportion (94%) of seroprotected subjects.  BMI did not predict seroconversion for any virus subtypes:  0.88 [0.59, 1.33], 1.38 [0.92, 2.06], and 1.27 [0.85, 1.90] for H1N1, H3N2, and B, respectively.  Age was inversely associated with seroprotection and seroconversion against H1N1, but not H3N2, vaccine components.  Age was also inversely associated with seroconversion to influenza B. 

    Conclusion: BMI was not independently associated with post-influenza vaccination seroprotection or seroconversion after adjusting for other clinical characteristics in this population of adults aged ≥ 50.

    Subject Category: E. Innate and adaptive immunity to infections, including vaccine immunology

    Laura A. Coleman, PhD1, H. Keipp Talbot, MD, MPH2, Kimberly Crimin, PhD2, Yuwei Zhu, MD, MS3, Michael T. Rock, PhD4, Jennifer Meece, PhD1, David K. Shay, MD, MPH5, Edward Belongia, MD1 and Marie Griffin, MD, MPH2, (1)Marshfield Clin Res Fndn, Marshfield, WI, (2)Vanderbilt Univ., Nashville, TN, (3)Vanderbilt University School of Medicine, Nashville, TN, (4)Vanderbilt University Medical Center, Nashville, TN, (5)Centers for Disease Control and Prevention, Atlanta, GA


    L. A. Coleman, None

    H. K. Talbot, Sanofi Pasteur: Investigator, Research support
    Pfizer: Investigator, Research support

    K. Crimin, None

    Y. Zhu, None

    M. T. Rock, None

    J. Meece, None

    D. K. Shay, None

    E. Belongia, None

    M. Griffin, None

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