Decline in Infant Pertussis Incidence in the U.K. After Introduction of Maternal Immunization

Pertussis incidence has risen in recent years. In the U.S., infants (age, <1 year) have the highest incidence and a case fatality rate of about 2%. In an effort to protect infants through placental transfer of pertussis antibodies, the CDC recommended in October 2012 that all pregnant women receive a dose of tetanus toxoid, diphtheria toxoid, and acellular pertussis (Tdap) vaccine during the third trimester of pregnancy; a similar recommendation was issued nearly simultaneously in the U.K. In the first study to assess the effectiveness of this strategy, British investigators examined associations between maternal vaccination status and confirmed cases of pertussis in infants born between 2008 and 2013.

In a representative sample of pregnant …