How long does the diptheria, tetanus and pertussis vaccine last?

5-10 years. You recieve doses of dtap at 2mo, 4mo, 6mo and then 15mo. Then a booster again at 4 years of age. Then another at age 11. And then every 5-10 years (according to some experts). If fully immunized.
I0Years if fully imm. If fully immunized with 6 shots given in childhood you are immune to all three Diptheria,Tetanus&Whooping Cough(Pertusses) A booster is adviced every 10 years The first 5 shots are given at age2,4,6,15-18 months and 4-6 years and these days Tdap is recommended at age of 11.