Halperin SA, et al. - An observer-blinded, randomized controlled trial was performed to assess the safety and immunogenicity of revaccination with tetanus-diphtheria-acellular pertussis vaccine (Tdap) in adults 10 years (aged 18 to <65 years) after a previous dose. Findings revealed that in these adults, a second dose of Tdap vaccine was well tolerated and immunogenic. Findings thereby could facilitate consideration of providing Tdap booster doses to adults.