1901. Effect of Pregnancy on Antibody Response to Seasonal Influenza Immunization
Session: Poster Abstract Session: Vaccines: Influenza
Saturday, October 10, 2015
Room: Poster Hall
Posters
  • IDWeek poster 10.2.15.pdf (392.1 kB)
  • Background:

    Healthy pregnant women are at increased risk of morbidity and mortality from influenza infection, and our previous study demonstrated decreased immunogenicity of inactivated influenza vaccines (IIV) administered during pregnancy. We analyzed antibody responses to seasonal influenza immunization over three influenza seasons to evaluate differences in vaccine response induced by pregnancy. 

    Methods:

    We enrolled 105 pregnant women and 106 non-pregnant women ages 18-39 years old during three influenza seasons: 2011-12, 2012-13, and 2014-15. We obtained blood on day 0 prior to IIV administration, as well as on day 28 post-immunization. We used the serum hemagglutination inhibition (HAI) assay to assess antibody responses, and we compared pre-vaccine geometric mean titers (GMTs), post-vaccine GMTs, geometric mean ratios (GMRs), percent seroconversion, and percent seroprotection between groups for each antigen.

    Results:

    Pre-vaccine GMTs at day 0 were similar between all groups, except non-pregnant women had higher GMTs for A/California (H1N1) in 2014 (p=0.048). Post-vaccine GMTs at day 28 were significantly higher in non-pregnant women for A/California (H1N1) in 2011 (p=0.027), A/Victoria (H3N2) in 2011 (p=0.037), B/Wisconsin in 2012 (p=0.039), and B/Brisbane in 2014 (p=0.011). Other GMTs were similar between pregnant and non-pregnant women; GMRs, seroconversion, and seroprotection were statistically similar between groups.

    Conclusion:

    We demonstrated significantly decreased antibody response to IIV in pregnant women compared to non-pregnant women for four different influenza vaccine antigens over three influenza seasons. These results suggest that pregnancy influences the antibody response to IIV influenza vaccination. 

    2014

     

    B/Brisbane

    Pregnant (N = 34)

    Not Pregnant (N = 40)

    p value

    Pre-Vaccine GMT

    32.68

    39.55

    0.198

    Post-Vaccine GMT

    98.43

    154.35

    0.011

    2012

     

    B/Wisconsin

    Pregnant (N=42)

    Not Pregnant (N=44)

    p value

    Pre-Vaccine GMT

    8.07

    10.32

    0.102

    Post-Vaccine GMT

    19.03

    28.06

    0.039

    2011

     

    A/California (H1N1)

    Pregnant (N = 29)

    Not Pregnant (N = 22)

    p value

    Pre-Vaccine GMT

    53.29

    53.11

    0.994

    Post-Vaccine GMT

    152.53

    300.46

    0.027

    A/Perth (H3N2)

     

     

     

    Pre-Vaccine GMT

    90.16

    150.23

    0.110

    Post-Vaccine GMT

    141.98

    240.99

    0.037

    Elizabeth P. Schlaudecker, MD, MPH1, Monica Mcneal, MS2, Mark C. Steinhoff, MD, FIDSA1 and Fred Finkelman, MD3, (1)Division of Infectious Diseases, Global Health Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, (2)Division of Infectious Diseases, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, (3)Division of Immunobiology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH

    Disclosures:

    E. P. Schlaudecker, None

    M. Mcneal, None

    M. C. Steinhoff, None

    F. Finkelman, None

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