Antibody in Breastmilk Following Pertussis Vaccination in Three-time Windows in Pregnancy

Area of Science:

• Immunology
• Maternal and Infant Health
• Vaccinology

Background:

• Pertussis-containing vaccines are recommended during pregnancy in the UK (16-32 weeks gestation).
• Debate exists regarding optimal vaccination timing for maternal and infant benefits.
• Breast milk IgA is vital for infant mucosal immunity, and its concentration may be influenced by maternal vaccination timing.

Purpose of the Study:

• To investigate if the timing of maternal pertussis vaccination during pregnancy impacts breast milk IgA concentrations.
• To assess antigen-specific IgA levels in colostrum and mature breast milk following different vaccination schedules.

Main Methods:

• Participants received pertussis-containing vaccines at different gestational periods (before 24 weeks, 24-27+6 weeks, or 28-31+6 weeks).
• Colostrum and breast milk samples were collected within 24 hours of delivery and at 14 days postpartum, respectively.
• Multiplex immunoassay was used to measure specific IgA levels against pertussis toxin, pertactin, tetanus toxoid, and diphtheria toxoid.

Main Results:

• No significant differences in specific IgA levels against tested antigens were observed between vaccination timing groups.
• A general decline in antigen-specific IgA levels was noted from colostrum to breast milk at 14 days postpartum for all participants.

Conclusions:

• The timing of pertussis-containing vaccine administration during pregnancy does not appear to influence the concentration of antigen-specific IgA in colostrum or breast milk at 14 days.
• These findings support current vaccination guidelines, suggesting flexibility in timing without compromising this aspect of passive immunity transfer.