What is Diphtheria?

Diphtheria is a serious infection caused by toxins of the bacteria Corynebacterium diphtheriae. The bacteria spread from person to person through respiratory droplets in the air from coughing, sneezing or talking. It can also be spread to a person if they touch open sores or ulcers from someone who is infected.

Diphtheria infects the respiratory system, or parts of the body that are used in breathing, and the skin.

What are the symptoms and complications of diphtheria?

The symptoms of diphtheria are slightly different depending on the body part that is affected. When the bacteria infect the lining of the respiratory system, symptoms include:

  • Weakness or fatigue
  • Sore throat
  • Fever
  • Swollen glands in the neck
  • Problems breathing
  • Difficulty swallowing

The toxin from the bacteria kills healthy tissue in the respiratory system. Within a few days, the dead tissue forms a thick gray coating that can build up in the throat or nose, making it difficult to breathe and swallow.

Respiratory diphtheria can be very serious and fatal if not treated. Even with treatment, about one in 10 patients with respiratory diphtheria die. Without treatment, up to half of patients can die from the disease.

When the bacteria infect the skin, it can cause open sores or ulcers. The diphtheria skin infection rarely results in any other severe symptoms or illness.

If the toxin from the bacteria gets into the bloodstream, it can potentially cause heart, nerve and kidney damage.

Who should get the diphtheria vaccine?

The CDC recommends people of all ages get the diphtheria vaccine.

Today there are four vaccines that help protect against diphtheria. All of these also protect against other diseases as well, and different vaccines are used depending on a person’s age.

  • DT – protects against diphtheria and tetanus
  • DTaP – protects against diphtheria, tetanus and pertussis
  • Td – protects against tetanus and diphtheria
  • Tdap – protects against tetanus, diphtheria and pertussis

Babies and children younger than seven years old receive DTaP or DT vaccines a total of five times:

  1. 2 months of age
  2. 4 months of age
  3. 6 months of age
  4. 15 to 18 months of age
  5. 4 to 6 years of age


Preteens should receive the Tdap booster between 11 and 12 years of age. Adults should receive another dose of either Tdap or Td every 10 years.

Pregnant women should also get the Tdap vaccine during the third trimester of any pregnancy.

Talk with your healthcare provider on which diphtheria vaccine is right for you.

Is the diphtheria vaccine effective?

Research has found the diphtheria vaccines are safe and 95 percent effective for up to 10 years.

The diphtheria vaccine started being routinely used in the 1940s. Today, the disease is not commonly heard of in the U.S. thanks to a successful immunization program. Before vaccines were available, diphtheria was a leading cause of childhood death around the world.

Even though it is rare in the U.S., diphtheria cases are still recorded worldwide. The best way to prevent the disease is through vaccination.

Most people do not experience any serious side effects from the vaccine, although some may occur. Most side effects are mild and do not impact a person’s ability to continue daily activities.