Vaccines against Group B streptococcus (GBS) are currently being developed. Data on natural immunity in various age groups will assist in the development of a GBS vaccination programme. Between August 2016 and July 2017, thirty serum samples were obtained from three age groups (neonates/infants, pregnant women, and the elderly) for this investigation. A GBS multiplex opsonophagocytic killing test (MOPA) against serotypes Ia, III, and V was used to determine serotype-specific opsonophagocytic activity (OPA). The mean OPA titers for serotype Ia were not statistically different among the three age groups, but were lower in neonates/infants. The mean OPA titer of neonates/infants for serotype III and V was considerably lower than that of pregnant women and the elderly.
In conclusion, despite high mother titers, the lower levels of OPA titers against all tested serotypes in neonates/infants suggest that intrapartum GBS vaccinations may be necessary for effective placental transfer of serotype-specific GBS antibodies with high avidity.
Reference: https://www.tandfonline.com/doi/full/10.1080/21645515.2019.1688036
