If you have already had whooping cough, will getting vaccinated do anything?

Boosts immunity: Unfortunately, whooping cough (pertussis) is a bacterial disease like strep throat.If you had it, you will likely have some immunity to it, but that will decline over the years. After 5-10 years you can be susceptible to re-infection & develop the persistent "100 days cough" that goes with it as well as being a carrier & spreading it throughout the community. Shots help you avoid recurrent disease.