Diphtheria is a serious bacterial infection caused by the bacterium Corynebacterium diphtheriae. It primarily affects the throat and nose, leading to symptoms such as a sore throat, fever, and a thick gray or white coating in the throat. If left untreated, diphtheria can cause severe complications, including difficulty breathing and heart problems. Vaccination is the best way to prevent diphtheria. The diphtheria vaccine is often given in combination with vaccines for tetanus and pertussis, known as the DTaP vaccine. Early diagnosis and treatment with antibiotics and antitoxins are crucial for recovery.