The tetanus, diphtheria, and acellular pertussis vaccine (Tdap) is recommended for all adults in both Canada and the United States. There are few data on the proportion of Canadian adults vaccinated with Tdap; however, anecdotal reports indicate that uptake is low. This study aimed to explore the knowledge, attitudes, beliefs, and behaviors of Canadian health care providers (HCPs) in an attempt to identify potential barriers and facilitators to Tdap uptake. HCPs were surveyed and a geographic and practice representative sample was obtained (N =1,167). In addition, 8 focus groups and 4 interviews were conducted nationwide. Results from the survey indicate that less than half (47.5%) of all respondents reported being immunized with Tdap themselves, while 58.5% routinely offer Tdap to their adult patients. Knowledge scores were relatively low (63.2% correct answers). The best predictor of following the adult Tdap immunization guidelines was awareness of and agreement with those recommendations. Respondents who were aware of the recommendations were more likely to think that Tdap is safe and effective, that their patients are at significant risk of getting pertussis, and to feel that they have sufficient information (p < 0.0001 for each statement). Focus group data supported the survey results and indicated that there are substantial gaps in knowledge of pertussis and Tdap among Canadian HCPs. Lack of public knowledge about adult immunization, lack of immunization registries, a costing differential between Td and Tdap, workload required to deliver the vaccine, and vaccine hesitancy were identified as barriers to compliance with the national recommendations for universal adult immunization, and suggestions were provided to better translate recommendations to front-line practitioners.
Keywords: Tdap; adult immunization; attitudes; beliefs; knowledge; pertussis; pertussis vaccine; vaccine coverage.