How about if you actually had WC as a younker?? Does that yield a more permanent immunity??
Can you get pertussis more than once?
Reinfection appears to be uncommon but does occur. With natural infection, immunity to pertussis will likely wane as soon as seven years following disease; reinfection may present as a persistent cough, rather than typical pertussis.
"Neither vaccination nor natural infection with pertussis guarantees lifelong protective immunity against pertussis. Since immunity decreases after five to ten years from the last pertussis vaccine dose, older children, adolescents and adults are at risk of becoming infected with pertussis and need vaccination."