Barriers to early uptake of tetanus, diphtheria and acellular pertussis vaccine (Tdap) among adults-United States, 2005-2007

Background: The tetanus, diphtheria and acellular pertussis vaccine (Tdap) was recommended by the Advisory Committee on Immunization Practices (ACIP) for U.S. adults in 2005. Our objective was to identify barriers to early uptake of Tdap among adult populations. Methods: The 2007 National Immunization Survey (NIS)-Adult was a telephone survey sponsored by the Centers for Disease Control and Prevention (CDC). Immunization information was collected for persons aged >= 18 years on all ACIP-recommended vaccines. A weighted analysis accounted for the complex survey design and non-response. Results: Overall, 3.6% of adults aged 18-64 years reported receipt of a Tdap vaccination. Of unvaccinated respondents, 18.8% had heard of Tdap, of which 9.4% reported that a healthcare provider had recommended it. A low perceived risk of contracting pertussis was the single most common reason for either not vaccinating with Tdap or being unwilling to do so (44.7%). Most unvaccinated respondents (81.8%) indicated a willingness to receive Tdap if it was recommended by a provider. Conclusions: During the first two years of availability, Tdap uptake was likely inhibited by a low collective awareness of Tdap and a low perceived risk of contracting pertussis among U.S. adults, as well as a paucity of provider-to-patient vaccination recommendations. Significant potential exists for improved coverage, as many adults were receptive to vaccination. Published by Elsevier Ltd.