Image of hand holding a piece of paper with the word Diphtheria

Diphtheria Vaccine

Diphtheria [dif-theer-ee-uh, dip-] is a bacterial infection that causes a thick covering on the back of the throat, breathing problems, paralysis, heart failure, or death. Children get 5 doses of the diphtheria vaccine starting at 2 months old. Adults need booster shots every 10 years.

What is diphtheria?

Bacteria which cause diphtheria
Bacteria which cause diphtheria Corynebacterium diphtheriae, 3D illustration

Diphtheria is a highly-contagious infection of the airways or skin. It is caused by the toxin-producing bacteria Corynebacterium diphtheriae, sometimes also called “c diphtheriae”. It creates a thick gray covering in the back of the throat called the “pseudomembrane” that interferes with breathing. The coating can cover the tissue of the nose, tonsils, voice box, and/or throat, making it very hard to breathe and swallow. Toxins in the bacteria can also cause serious complications like paralysis, heart failure, or death.

What is respiratory diphtheria?

Respiratory diphtheria is an infection of the airways. It starts with a sore throat and fever. Bacteria colonize the back of the throat and create a thick gray-white coating (membrane), which can cause breathing problem and widespread inflammation in the lungs.

There are three types of respiratory diphtheria:

  • Nasal diphtheria
  • Pharyngeal and tonsillar diphtheria
  • Laryngeal diphtheria

What is cutaneous (skin) diphtheria?

Diphtheria on the skin causes a painful rash with pus-filled blisters. The blisters turn into open sores surrounded by a patch of reddish skin. The sores heal within 2-3 months, often leaving scars. Infections are treated with antibiotics. Skin infections with diphtheria are very rare in the U.S., but very common in tropical countries.

How many people get diphtheria?

Diphtheria caused 206,000 illnesses and 15,520 deaths in the U.S. in 1921, but vaccines introduced in the 1920s have nearly eradicated the

disease. There were only 6 illnesses in the U.S. from 2000 to 2013.

What are the symptoms of diphtheria?

  • Sore throat
  • Fever
  • Muscle weakness
  • Tiredness
  • Loss of appetite
  • Enlarged lymph nodes in the neck, sometimes referred to as a “bull neck”
  • Grayish membrane over the nose, throat, or tonsils
  • Problems breathing
  • Pain when swallowing
  • Cough
  • Hoarseness
  • Nasal discharge (foul-smelling, bloodstained)
  • Headache

How soon do symptoms appear?

The symptoms usually appear within 2-5 days after exposure, with a range of 1-10 days. Not everyone has symptoms. These people are “carriers,” which means they spread diphtheria without feeling sick.

Can diphtheria cause death?

Yes. Death occurs in 5-10% of all cases of respiratory diphtheria. Up to 20% of infections are deadly in children under 5 years old, or adults over 40 years old. Before there was treatment for diphtheria, up to 50% of cases were deadly.

What are complications of diphtheria?

  • Breathing Problems: Diphtheria can block the throat, paralyze nerves needed to swallow or breathe, and cause severe lung inflammation that permanently reduces lung function.
  • Heart Damage: Diphtheria toxins can cause inflammation of heart muscles (myocarditis), slow heartbeat (bradycardia), congestive heart failure, or sudden death.
  • Nerve Damage: Neurological complications can occur up to 6 weeks after the first symptoms of diphtheria. It often causes muscle weakness in the arms and legs.
  • Paralysis: Diphtheria can paralyze a breathing muscle (diaphragm) within 30 minutes or up to 6 weeks after the first symptoms of diphtheria. Patients may need to use a respirator.
  • Bladder Dysfunction: Patients with nerve damage may be unable to empty the bladder, urinate more often, pass only small amounts of urine, or lose bladder control (incontinence).
  • Malignant Diphtheria: The most severe form of diphtheria, also known as “hypertoxic diphtheria” or “diphtheria gravis,” causes bleeding problems, kidney failure, or death.

How do you get diphtheria?

Diphtheria usually spreads in the air when a non-infected person breathes droplets from the cough or sneeze of an infected person. It can also spread by touching the discharge from an infected person’s eyes, nose, throat, or skin — or handling their used tissues, unwashed utensils, drinking glasses, towels, toothbrush, or toys.

How long is diphtheria contagious?

Untreated patients with diphtheria can be contagious for up to 6 weeks, even if they do not have symptoms. With proper treatment, the contagious period can be shortened 48 hours.

How is diphtheria treated?

Diphtheria is a life-threatening medical emergency that requires hospitalization. Patients are isolated and given the anti-toxin to diphtheria and 2 weeks of antibiotics like penicillin and erythromycin. Heart problems and other complications will require specialized treatment. Nerve damage may not appear for up to 6 weeks, so prolonged hospitalization is usually necessary. Recovery is very slow.

Can I get diphtheria again?

Yes. Past infection with diphtheria does NOT give you lifelong immunity or prevent future infections.

What is the diphtheria vaccine?

The first inactivated toxin (toxoid) against diphtheria was created in 1921, but vaccines were not widely-used until the 1930s. When administered in a vaccine, the toxoid triggers an immune response that teaches the body to develop immunity against diphtheria.

What is the diphtheria antitoxin?

The diphtheria anti-toxin was first used in the U.S. in 1891 and is now produced in horses. The anti-toxin does not get rid of toxins that are already in the body. Instead, it neutralizes any of the poison circulating in the bloodstream and prevents the disease from getting worse.

Did it inspire the Alaskan Iditarod?

Yes. In January 1925, the diphtheria anti-toxin was transported by dog sled relay across Alaska by 20 mushers and over 150 dogs for 5.5 days, saving the small town of Nome from a deadly outbreak of diphtheria. This story of diphtheria history inspired the Iditarod Sled Dog Race.

How effective is the diphtheria vaccine?

The first three doses of the DTaP vaccine are 80-85% effective at preventing diphtheria in children. With full immunization and booster shots, diphtheria vaccines are estimated to protect 95% of people for approximately 10 years. Protection decreases over time, so booster shots are needed at age 12 and every 10 years afterward in adults for prevention.

Who should NOT get vaccinated?

  • People who are allergic to the vaccine or its ingredients
  • People who are sick — wait until you get better
  • Children who had brain or nerve damage within 7 days

Ask a doctor if your child had severe pain or swelling after a vaccine, nervous system problems, Guillian-Barré Syndrome (GBS), high fever over 105°F, seizure, collapsed, or cried non-stop for 3 hours or more.

What is the immunization schedule for diphtheria?

The immunization schedule for the DTaP vaccine in children is a series of 5 shots at the following ages:

  • 2 months
  • 4 months
  • 6 months
  • 15 to 18 months
  • 4 to 6 years

Do I need a booster shot?

Yes. The diphtheria vaccines only lasts for 10 years, so children need a booster shot of the DTaP vaccine around age 12. Adults should get a booster shot of the tetanus-diphtheria (Td) vaccine or tetanus-diphtheria-pertussus (Tdap) vaccine every 10 years.

What type of diphtheria vaccine can I get?

The FDA has approved 11 types of diphtheria vaccines. All of them are combined with other vaccines.

Children under 7 years old get a 5-dose series of DTaP. Another option is the DT vaccine for children who should not get vaccines that contain pertussis (whooping cough). DT should not be given to anyone over 7 years old.

  • DT Vaccine: Diphtheria and pertussis — generic
  • DTaP Vaccine: Diphtheria, tetanus, and pertussis — Daptacel®, Infanrix®, Kinrix®, Pediarix®, Pentacel®, and Quadracel®

Children over 7 years old get the Tdap vaccine around the age of 12. Adults can also get Tdap if they did not get it at age 12. Afterward, adults get the Td vaccine in a one-dose booster shot every 10 years:

  • Td Vaccine: Tetanus and diphtheria — Tenivac® and generic
  • Tdap Vaccine: Tetanus, diphtheria, and pertussis — Adacel®and Boostrix®

Is the vaccine required for school or daycare?

All 50 states require 3-5 doses of the diphtheria vaccine for children entering Kindergarten. With the exception of Ohio, 3-5 doses of the diphtheria vaccine are required for children entering daycare Most states require Td vaccine or Tdap booster shots or children entering middle school (Grades 6-12) or children over age 11. Some states offer religious exemptions. Visit for more information.

Is the diphtheria shot safe?

Yes. However, the diphtheria vaccine can cause severe side effects. The Vaccine Injury Compensation Program (VICP) covers children who had anaphylaxis within 4 hours, brachial neuritis (nerve damage) within 2-28 days, and encephalopathy or encephalitis (brain inflammation) within 72 hours of receiving DTaP, DTP, DT, or Td.

What are the most common vaccine side effects?

The most common side effects of the DTaP vaccine in children are:

  • Fussiness (33%)
  • Fever (25%)
  • Redness or swelling (25%)
  • Soreness or tenderness (25%)
  • Tiredness or poor appetite (10%)
  • Swelling of the entire arm or leg for 1-7 days (3.3%)
  • Vomiting (2%)

What are the most severe vaccine side effects?

The most severe side effects of the DTaP vaccine in children include:

  • Seizure, jerking or staring (1 in 14,000)
  • Non-stop crying for 3 hours or more (1 in 1,000)
  • High fever over 105°F (1 in 16,000)
  • Allergic reaction (1 in 1,000,000)
  • Long-term seizures
  • Coma
  • Lowered consciousness
  • Permanent brain damage
  • Behavior changes
  • Death

Can the diphtheria vaccine cause diphtheria?


What other ingredients are in the vaccine?

All diphtheria vaccines contain low levels of other ingredients like aluminum, formaldeyhde, thimerosal (mercury), preservatives, antibiotics (neomycin, 2-Phenoxyethanol), and cow or monkey tissues. Visit the CDC Vaccine Ingredient Summary for a complete list of ingredients by vaccine.

To learn more about the side effects associated with the Diphtheria vaccine, please visit this page: Diphtheria Vaccine Side Effects

Where can I get more information?

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If you or a loved one has been the victim of a vaccine side effect, you should contact a vaccine lawyer with experience in this type of complex litigation.

We have recently partnered with Schmidt & Clark, LLP; a Nationally recognized law firm who handles vaccine lawsuits in all 50 states.

The lawyers at the firm offer a Free Confidential Case Evaluation and may be able to obtain financial compensation for you or a loved one by filing a vaccine lawsuit or claim with The National Vaccine Injury Compensation Program. Contact Schmidt & Clark today by using the form below or by calling them directly at (866) 223-3784.