Tetanus, diphtheria, and pertussis (Tdap) are infectious bacterial diseases. Without treatment, they can lead to severe complications, and in some instances, they are fatal. The Tdap vaccine protects against all three diseases. The Tdap vaccine is highly effective. Since the introduction of vaccines, cases of diphtheria and tetanus have dropped by 99% , while cases of pertussis have dropped by 80%. Doctors can give Tdap as a primary immunization or as a booster vaccine, meaning it "tops up" the immunity a person already has to an illness. In this article, we will discuss what the Tdap vaccine is, how safe it is, who should get it, and possible side effects. Tdap is a booster vaccine. It protects people from the following illnesses. Tetanus Tetanus is an infectious disease due to bacteria in soil and feces. These microbes can enter the body through cuts and wounds. When they begin to multiply, they produce a toxin that causes painful muscle contractions and spasms. These contr...