709. Do Low Vitamin D Levels Explain Poorer Influenza Vaccine Immunogenicity among HIV-Infected and HIV-Uninfected Adults?
Session: Poster Abstract Session: Vaccines
Thursday, October 27, 2016
Room: Poster Hall
Posters
  • Vit D poster IDSA FINAL.pdf (481.8 kB)
  • Background:  Vaccination is the most important preventive strategy against influenza, however post-vaccination antibody responses are often inadequate especially among HIV-infected (HIV+) persons.  Vitamin D deficiency is prevalent especially among HIV+ adults, and low 25-hydroxyvitamin D [25(OH)D] levels may adversely affect immune responses.  We evaluated the association between 25(OH)D levels and post-influenza vaccination responses.

    Methods:  We conducted a prospective cohort study evaluating the immunogenicity of monovalent influenza A (H1N1) vaccination among HIV+ and HIV- adults (18-50 years of age) during the 2009-2010 influenza season.  Antibody titers were evaluated at baseline, day 28, and 6 months post-vaccination using hemagluttination inhibition assays.  Serum 25(OH)D levels were measured at day 28.  Univariate and multivariate regression analyses examined the association between 25(OH)D levels [categorized as <20 ng (deficiency) vs. >20 ng] with the primary outcome of post-vaccination seroconversion.  Secondary outcomes included seroprotection; a ≥4-fold increase in titers; and GMTs post-vaccination.  Analyses were repeated evaluating the 25(OH)D level as a continuous variable.

    Results:  A total of 128 adults (64 HIV+ and 64 HIV-) were included.  HIV+ had a median CD4 count 580 cells/mm3.  Seroconversion at day 28 post-vaccination was achieved in fewer HIV+ compared with HIV- participants (56% vs. 74%, p=0.03).  Similarly, HIV+ persons had lower GMTs at day 28 (269 vs. 80, p=0.003) and 6 months (113 vs. 20, p=0.0002) post-vaccination.  Vitamin D deficiency was more prevalent among HIV+ vs. HIV- persons (25% vs. 17%), although not significantly different (p=0.39).  There were no associations found between lower 25(OH)D levels and poorer antibody responses at day 28 or month 6 post-vaccination for any of the study outcomes among either HIV+ or HIV- adults.

    Conclusion:  Vitamin D deficiency was common among both HIV+ and HIV- adults, but lower levels did not predict antibody responses after H1N1 (2009) influenza vaccination.  Low 25(OH)D levels do not explain the poorer post-influenza vaccination responses among HIV+ persons.  Further research is needed to improve vaccine immunogenicity especially among HIV+ persons.

    Nancy Crum-Cianflone, MD, MPH1,2,3, Seunghyun Won, PhD1,4, Rachel Lee, MD5, Tahaniyat Lalani, MD1,4,6, Anuradha Ganesan, MD, MPH1,4,7, Timothy Burgess, MD1 and Brian Agan, MD1,4, (1)Infectious Disease Clinical Research Program, Department of Preventive Medicine and Biostatistics, Uniformed Services University of the Health Sciences, Bethesda, MD, (2)Scripps Mercy Hospital, San Diego, CA, (3)Naval Medical Center San Diego, San Diego, CA, (4)Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, (5)Operational Infectious Diseases, Naval Health Res. Ctr., San Diego, CA, (6)Naval Medical Center Portsmouth, Portsmouth, VA, (7)Walter Reed National Military Medical Center, Bethesda, MD

    Disclosures:

    N. Crum-Cianflone, None

    S. Won, None

    R. Lee, None

    T. Lalani, None

    A. Ganesan, None

    T. Burgess, None

    B. Agan, None

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