Prior to large scale immunization programs introduced in the 1940s, pertussis, or whooping cough, was a leading cause of childhood mortality. Despite this, pertussis has experienced a resurgence in recent decades, the cause for which remains a contested subject. One hypothesis suggests that immunological blunting—where maternally transferred antibodies potentially interfere with the infant’s immune response to their own vaccinations—may be contributing to this. CEID members Tobias S. Brett and Pejman Rohani are authors on a new study investigating the effectiveness of maternal pertussis (whooping cough) vaccination on infants and the potential blunting effect on the infants’ subsequent vaccinations.
To assess the long-term effects of maternal vaccination on pertussis incidence and vaccine effectiveness, the researchers performed systematic review and meta-analysis of empirical studies on the relative risk of pertussis after maternal and infant primary immunization. They then created a mathematical model simulating pertussis transmission dynamics over several decades, taking into account varying levels of maternal immunization coverage and blunting effects. The results reveal a complex interaction between maternal vaccination, blunting, and the overall effectiveness of pertussis vaccination programs.
These findings suggest that while maternal vaccination effectively protects newborns, the potential blunting effect on infants’ vaccinations may alter the long-term dynamics of pertussis transmission and vaccine effectiveness. To fully comprehend the epidemiological implications of maternal vaccination, further research is needed to precisely to what extent blunting occurs after primary immunization.
For more information, read the full paper here.