Fig 4.

Breast milk IgG and IgA antibodies against PT, PRN, FHA, DT, and TT in post-partum women immunized Adacel Tdap. Data represent antibody titers 0.5–6 months after post-partum Tdap vaccination. Breast milk samples were available for testing from 18 women at 2 weeks, 31 women at 6 weeks, and 19 women at 6 months. *P < 0.05, **P < 0.01, ***P < 0.001, and ****P < 0.0001 by Wilcoxon signed-rank test. DT, diphtheria toxoid; FHA, filamentous hemagglutinin; FIM, fimbriae; ns, not significant; PRN, pertactin; PT, pertussis toxin; TT, tetanus toxin.