How well does Tdap vaccine protect against tetanus, diphtheria and pertussis?
When Tdap vaccine is given as a booster shot for adolescents immunized in childhood, it protects virtually 100 per cent of people against tetanus, over 95 per cent of people against diphtheria and 85 per cent of adolescents against pertussis. Vaccination also makes these diseases milder for those who may catch them.
