A Trial to Evaluate the Safety and Immunogenicity of ADACEL® Vaccine in Persons 65 Years of Age and Older

It is well recognized that older adults can contract pertussis, suffer its complications, and unwittingly transmit it to close contacts, which may well include infants too young to have received their primary series of DTaP vaccinations. ADACEL® vaccine is currently licensed in the US for persons 11 - 64 years of age, but no pertussis vaccine is yet approved for administration to older adults. The most widely used Td vaccine in the US, DECAVAC®, has no upper limit on its age indication. The purpose of this trial is to describe the safety and immunogenicity of ADACEL® vaccine among individuals ≥ 65 years of age.