On Apr. 1, 2014, Sanofi Pasteur announced the U.S. Food and Drug Administration (FDA) had expanded the approved age indication of Adacel (Tetanus Toxoid, Reduced Diphtheria Toxoid and Acellular Pertussis Vaccine Adsorbed; Tdap) for active booster immunization for the prevention of tetanus, diphtheria, and pertussis as a single dose in persons 10 through 64 years of age.

The FDA approval was based on data from a Phase IV, open label, multi-center trial to evaluate the safety and immunogenicity of a single dose of Adacel vaccine in persons 10 years of age compared with those in persons 11 years of age. Antibody responses to all of the vaccine antigens (tetanus, diphtheria, and pertussis) and rates of adverse reactions were similar in the two age groups.

To reduce pertussis morbidity in adolescents and adults and maintain the standard of care for tetanus, diphtheria, and pertussis protection, the U.S. Centers for Disease Control and Prevention recommends that persons in these age groups receive a single dose of a Tdap vaccine because immunity from early childhood vaccination wanes over time.

Adacel vaccine was licensed in the United States by the FDA in June 2005 to address pertussis protection for people 11 through 64 years of age. Adacel vaccine provides demonstrated immunogenicity against tetanus, diphtheria, and pertussis, and has a safety profile similar to that of tetanus-diphtheria (Td) vaccine.

Pertussis, also known as whooping cough, is a highly contagious and often serious disease, especially in young children. In adolescents and adults, it often presents as a severe and episodic cough that may last for weeks and even months. Pertussis is caused by bacteria called Bordetella pertussis, found in the nose and throat of persons with the disease; it is spread through contact with respiratory droplets generated by coughing or sneezing