Diphtheria is a contagious illness caused by a type of bacteria. It can cause breathing and swallowing problems and can damage the heart and central nervous system (brain and spinal cord).
Diphtheria, though rare, can be fatal if not treated.
The DTaP (diphtheria-tetanus-pertussis) vaccine, given in childhood, protects against diphtheria infection. Tdap and Td vaccines are booster shots that give continued protection to teens and adults.
WebMD Medical Reference from Healthwise