A clinical trial looked at how pregnancy vaccination affects antibodies against pertussis in babies. The study included 47 pregnant women who received a DTaP booster and 22 who did not. Their infants received the standard hexavalent DTaP vaccine at six months of age. Researchers measured antibody levels and binding strength in the babies at five months old.
The main finding was that infants of unvaccinated mothers had higher concentrations of anti-pertussis toxin antibodies. These babies also showed higher ability to inhibit specific antibody targets compared to infants of vaccinated mothers. This suggests that the antibodies passed through the placenta were more effective in the unvaccinated group.
However, the increase in antibody strength after the infant received their own vaccine was greatest in those with lower starting levels. No safety concerns were reported in this small trial. Readers should note that this study was small and open-label, meaning results may not apply to everyone. The data shows a link between maternal vaccination status and infant antibody levels, but does not prove one method is better for all families.