Immunisation with a tetanus, diphtheria and pertussis vaccine during pregnancy can protect the youngest infants from pertussis, according to a study in JAMA Pediatrics.

Epidemiologist Tami Skoff, from the US Centers for Disease Control and Prevention in Atlanta, and colleagues compared pertussis incidence rates in the pre-maternal tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccination period (2000-10) and the post-maternal Tdap vaccination period (2012-19) for infants younger than two months (target group of maternal vaccination) versus infants aged 6-12 months.