Subscribe for the latest science breakdowns! And, become a member to chat 1:1 about science related topics! The Tdap vaccine is routine for individuals 7yrs or older to help prevent tetanus, diphtheria, and pertussis. Diphtheria and pertussis spread from person to person, while tetanus infects the body through open cuts or wounds. A Tdap booster is often necessary after 10years to continue to provide protection against the three infectious diseases.