NACI update on pertussis vaccination in pregnancy

I am writing on behalf of the National Advisory Committee on Immunization (NACI) in response to the Child Health Update by Drs Gilley and Goldman.¹ The National Advisory Committee on Immunization has published a review of the literature, along with a review of Canadian pertussis epidemiology and recommendations for protecting infants from pertussis. The NACI statement containing this information can be found online.² The review concluded that the pertussis vaccine has been shown to be safe and immunogenic in pregnant women. However, the effectiveness of maternal vaccination to prevent severe disease in newborns has not been established, and the potential of maternal vaccination to interfere with infants’ immune response to their infant pertussis vaccinations has not yet been defined. Therefore, NACI made the following recommendations.

• Pregnancy is an opportunity to review immunization status and offer pertussis vaccination to pregnant women at 26 weeks of gestation or greater if it has not already been received in adulthood (NACI recommendation, grade A). Immunization should not be delayed until close to delivery, as this might not provide sufficient time for optimal transfer of antibodies to the infant or direct protection of the infant against pertussis.

• Depending on regional epidemics, immunization with the tetanus toxoid, reduced diphtheria toxoid, and acellular pertussis vaccine might be offered during pertussis outbreaks (as defined by each jurisdiction) to pregnant women at 26 weeks of gestation or greater irrespective of their immunization histories (NACI recommendation, grade B). Jurisdictions should have the capacity to monitor local epidemics to make a decision to routinely encourage vaccination for pregnant women (NACI recommendation, grade A). Coverage and safety should be monitored (NACI recommendation, grade A).

• However, in view of the current pertussis epidemiology in Canada, NACI does not recommend immunization of all women against pertussis during pregnancy (NACI recommendation, grade E).

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