2282. Age-stratified analysis of serotype-specific immunity against group B streptococcus
Session: Poster Abstract Session: Miscellaneous Vaccines
Saturday, October 6, 2018
Room: S Poster Hall
Posters
  • 2018 ID week.pdf (135.1 kB)
  • Background: Development of group B streptococcus (GBS) vaccine is currently underway. In order to establish the immunization policy for the future, it is necessary to understand the basal immune level of risk groups in each country.

    Methods: Thirty serum samples were collected from each risk group (neonates/infants, pregnant women and the elderly) between August 2016 and July 2017 at Korea University Guro hospital. Serotype-specific opsonic index (OI) was assessed using GBS multiplex opsonophagocytic killing assay (MOPA) against serotype Ia, III and V, which are most prevalent worldwide.

    Results: The mean age of neonates/infants, pregnant women, and the elderly was 1.3 months (range, 1-3 months), 31.9 years (range, 23-41 years) and 68.8 years (range 65-76 years), respectively. Baseline OI of each risk group measured by MOPA was shown in table1. The mean OI of serotype Ia was not significantly different among three risk groups (p=0.156), but relatively lower in the neonates/infants group (mean ± standard deviation, 137 ± 278). For serotype III, the mean OI of neonates/infants (338 ± 623) was significantly lower compared to those of pregnant women (1377 ± 1167) and old adults (1350 ± 1741)(p=0.002); Overall 60% of neonates/infants showed OI below 100. As for the serotype V, OI was particularly lower in neonates/infants (161 ± 445) compared to the elderly (3669 ± 5597) and pregnant women (9414 ± 6394) with statistically significant differences between three risk groups (p<0.001).

    Conclusion: Considering the relatively low OI of neonates/infants despite high maternal titer, intrapartum GBS vaccination might be required to ensure efficient placental transfer of serotype-specific GBS antibodies with high avidity.

    Table 1. Comparison of baseline opsonic indexes between risk groups: mean opsonic indexes and 95% confidence intervals

    Serotypes

    Groups

    Opsonic index(mean)

    95%CI

    p-value

    Ia

    Neonates/infants

    137

    33-241

    0.596

    Pregnant women

    285

    17-552

    The Elderly

    231

    3-459

    III

    Neonates/infants

    338

    105-570

    0.002

    Pregnant women

    1377

    941-1813

    The elderly

    1350

    700 - 2000

    V

    Neonates/infants

    161

    -5-327

    <0.001

    Pregnant women

    9414

    6825-12003

    The elderly

    3669

    1579-5759

    Min Joo Choi, MD1, Saem Na Lee, MD1, Ye Seul Jang, MD1, Ji Yun Noh, MD1, Hee Jin Cheong, MD, PhD1, Woo Joo Kim, MD1, Shun-Mei Lin, Student2, Ho Seong Seo, PhD2, Dae Jin Song, MD1, Geum Joon Cho, MD1, Min Jeong Oh, MD1 and Joon Young Song, MD1, (1)Korea University College of Medicine, Seoul, Korea, Republic of (South), (2)Korea Atomic Energy Research Institute, Jeongeup, Korea, Republic of (South)

    Disclosures:

    M. J. Choi, None

    S. N. Lee, None

    Y. S. Jang, None

    J. Y. Noh, None

    H. J. Cheong, None

    W. J. Kim, None

    S. M. Lin, None

    H. S. Seo, None

    D. J. Song, None

    G. J. Cho, None

    M. J. Oh, None

    J. Y. Song, None

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