dtap what is
In this article. DTaP is a vaccine that helps children younger than age 7 develop immunity to three deadly diseases caused by bacteria: diphtheria, tetanus, and whooping cough (pertussis). Tdap is a booster immunization given at age 11 that offers continued protection from those diseases for adolescents and adults.ut since immunity to pertussis also wears off during childhood, a weaker form of the pertussis vaccine has been added to the booster to make the vaccine Tdap. The current recommendation is that one dose of the Tdap vaccine be substituted for one dose of the Td vaccine between the ages of 11 and 64.