Human Vaccines & Immunotherapeutics (Jun 2020)

Age-stratified analysis of serotype-specific baseline immunity against group B streptococcus

  • Min Joo Choi,
  • Ji Yun Noh,
  • A-Yeung Jang,
  • Hee Jin Cheong,
  • Woo Joo Kim,
  • Dae Jin Song,
  • Geum Joon Cho,
  • Min Jeong Oh,
  • Yong Zhi,
  • Ho Seong Seo,
  • Joon Young Song

DOI
https://doi.org/10.1080/21645515.2019.1688036
Journal volume & issue
Vol. 16, no. 6
pp. 1338 – 1344

Abstract

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Group B streptococcus (GBS) vaccines are currently under development. Data on the natural immunity in diverse age groups will aid establishing the GBS immunization policy. In this study, thirty serum samples were collected from three age groups (neonates/infants, pregnant women, and the elderly) between August 2016 and July 2017. Serotype-specific opsonophagocytic activity (OPA) was assessed using a GBS multiplex opsonophagocytic killing assay (MOPA) against serotypes Ia, III, and V. The mean OPA titers for serotype Ia of the three age groups were not significantly different (p = .156), but tended to be lower in neonates/infants (mean ± standard deviation, 137 ± 278). For serotype III and V, the mean OPA titer of neonates/infants (338 ± 623 and 161 ± 445, respectively) was significantly lower than that of pregnant women (1377 ± 1167 and 9414 ± 6394) and the elderly (1350 ± 1741 and 3669 ± 5597) (p = .002). In conclusion, the lower levels of OPA titers against all tested serotypes in neonates/infants, despite high maternal titers, indicates that intrapartum GBS vaccinations may be required for efficient placental transfer of serotype-specific GBS antibodies with high avidity.

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