Where did tdap come from?

Tdap is a combination vaccine that protects against three diseases: tetanus, diphtheria, and pertussis (whooping cough). The name "Tdap" reflects its components: "T" for tetanus, "d" for diphtheria (in reduced doses), and "ap" for acellular pertussis. This vaccine was developed to provide immunity against these illnesses while minimizing the side effects associated with older whole-cell pertussis vaccines. Tdap is recommended for adolescents and adults, particularly for those who will be around infants, to help prevent the spread of pertussis.