Render of Diphtheria

What is Diphtheria?

Diphtheria is an acute bacterial disease that usually affects the tonsils, throat, nose, and/or skin. The disease is passed from person to person by droplet transmission, usually by breathing in bacteria after an infected person has coughed, sneezed, or even laughed. It can also be spread by handling used tissues or by drinking from a glass used by an infected person. People can also get sick from touching infected sores on persons with the skin form of diphtheria. The diphtheria bacteria make a toxin that sickens people. Diphtheria can lead to breathing problems, heart failure, paralysis, and sometimes death.

  • Recovery from diphtheria is not always followed by lasting immunity, so even those persons who have survived the disease need to be immunized.


Although no longer a very common disease in the US, diphtheria remains a large problem in other countries and can pose a serious threat to people in the US who may not be fully immunized and who travel to other countries, or have contact with people coming to the US from other parts of the world.

  • Nearly 1 out of every 10 people who get respiratory diphtheria will die from it, even with treatment
  • Most cases of diphtheria occur among unvaccinated or inadequately vaccinated people


Signs and symptoms may vary from mild to severe. They usually start two to five days after exposure. Symptoms often come on fairly gradually, beginning with a sore throat and fever. In its early stages, diphtheria may be mistaken for a severe sore throat. Other symptoms include a low-grade fever and enlarged lymph nodes (swollen glands) located in the neck. Diphtheria can cause skin lesions that may be painful, red, and swollen.

People carrying diphtheria germs are contagious for up to four weeks without antibiotics, even if they themselves do not develop symptoms.


Vaccination is the best way to prevent diphtheria. Most children receive a first dose in the form of a combined vaccine called DTaP (diphtheria-tetanus-acellular pertussis). A booster dose is recommended for adolescents as Tdap (tetanus-diphtheria-pertussis) vaccine. Health officials now recommend that all adults receive at least 1 dose of Tdap, followed by booster doses of Tdap or Td (tetanus-diphtheria) vaccine every 10 years.


Treatment for respiratory diphtheria involves using antitoxin to stop the toxin made by the bacteria from damaging the body. Antibiotics may be used to kill and get rid of the bacteria for both infections in the respiratory system and on the skin.
Recovery from diphtheria is not always followed by lasting immunity, so even those persons who have survived the disease need to be immunized.


Updated March 2023

Source: Centers for Disease Control and Prevention

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