Predictors of Tetanus-Diphtheria-Acellular Pertussis Vaccination Among Adults Receiving Tetanus Vaccine in the United States: Data From the 2008 National Health Interview Survey

Background: The incidence of pertussis in the US has been increasing. Vaccination of adults is important to reduce disease burden and prevent transmission to infants at high risk of complications. The tetanus-diphtheria-acellular pertussis (Tdap) vaccine has been available in the US since 2005 and is indicated as a one-time replacement for the routine adult tetanus-diphtheria (Td) booster. This vaccine has been underutilized in the adult population.

Objectives: The purpose of this study is to identify predictors of adult acellular pertussis (Tdap) vaccination in people receiving Td.

Methods: National Health Interview Survey data from 2008 were analyzed in 2011. Respondents were 18-64 years of age, received tetanus vaccination during 2005-2008, and were aware if it contained pertussis. Predictors of Tdap were identified using multivariate logistic regression.

Results: Overall, 51.1% of respondents received Tdap. College education was associated with higher odds of vaccination compared to lower education levels [OR 1.55 (95% CI 1.16-2.07)]. Having 2-3 office visits [OR 2.01 (95% CI 1.32-3.06)] or 4-9 visits [OR 1.60 (95% CI 1.06-2.42)] in the previous year increased the odds compared to no visits. Vaccination was less likely for those 50-64 years old compared to 18-24 years old [0.61 (95% CI 0.38-0.96)]. Individuals with functional limitation had lower odds compared to no limitation [0.70 (95% CI 0.54-0.91)].

Conclusions: In 2008, 51.1% of adult Td vaccinations included pertussis, suggesting continued efforts to remove barriers are needed. Interventions should target older, functionally impaired, and educationally disadvantaged populations.