Trends in Canadian infant pertussis hospitalizations in the pre- and post-acellular vaccine era, 1981-2016.

•Pertussis-related hospitalization and ICU admission rates have reduced for infants <1 y.o.•Infants <2 months of age have highest burden of pertussis-related hospitalization.•Maternal immunization programs to decrease this burden have been introduced.•Further monitoring and evaluation of this policy change should be undertaken.