Consumer edition active

Diphtheria-Tetanus-Pertussis Vaccine

ByMargot L. Savoy, MD, MPH, Lewis Katz School of Medicine at Temple University
Reviewed/Revised Modified Jul 2025
v16233772
VIEW PROFESSIONAL VERSION

The diphtheria, tetanus, and pertussis vaccine is a combination vaccine that protects against these 3 diseases:

  • Diphtheria usually causes inflammation of the throat and mucous membranes of the mouth. However, the bacteria that cause diphtheria produce a toxin that can damage the heart, kidneys, and nervous system. Diphtheria was once a leading cause of death in children.

  • Tetanus (lockjaw) causes severe muscle spasms, which result from a toxin produced by bacteria. The bacteria usually enter the body through a wound.

  • Pertussis (whooping cough) is a very contagious respiratory infection that is particularly dangerous to children younger than 2 years old and to people who have a weakened immune system.

(See also Overview of Immunization.)

Vaccine Type

The diphtheria, tetanus, and pertussis vaccine is a toxoid vaccine, which means it contains weakened toxins (called toxoids) that are produced by the bacteria that cause tetanus or diphtheria but have been modified to be harmless. The vaccine also contains an acellular component of the bacteria that causes pertussis. Because the toxoids and the component are harmless, they cannot cause tetanus, diphtheria, or pertussis, but they do trigger a strong response from a person's immune system (see Active immunization).

The vaccine has 2 formulations:

  • DTaP (diphtheria-tetanus-pertussis) for children under 7 years of age

  • Tdap (tetanus-diphtheria-pertussis) for people 7 years of age and older (mostly adolescents and adults)

Tdap contains lower amounts of the diphtheria and pertussis components, which is indicated by the lower case d and p. The lower amounts are adequate to induce immunity in adolescents and adults.

Combination vaccines with DTaP vaccine, hepatitis B vaccine, inactivated poliovirus vaccine, and Haemophilus influenzae type b vaccine are also available in the United States.

There is also a separate vaccine that contains only the tetanus and diphtheria components (tetanus-diphtheria [Td] vaccine).

Dose of and Recommendations for Diphtheria-Tetanus-Pertussis Vaccine

The DTaP vaccine is given as 5 separate injections into a muscle.

The Tdap vaccine is given as 1 injection into a muscle.

People who should receive this vaccine

The DTaP vaccine is a routine childhood vaccination. Five total shots of DTaP are given typically at age 2 months, 4 months, 6 months, 15 to 18 months, and 4 to 6 years (see CDC: Recommended Immunizations for Birth Through 6 Years Old, United States, 2025).

The Tdap vaccine is also a routine childhood vaccination. It is given as 1 lifetime dose at age 11 to 12 years (known as a booster shot). The Tdap booster shot is also given to people 13 years of age and over who have never received Tdap or who are unsure about whether they received it. This booster shot is followed by another Tdap or Td booster shot every 10 years (see CDC: Recommended Immunizations for Children 7-18 Years Old, United States, 2025).

Pregnant people are given a dose of Tdap during each pregnancy (preferably between 27 and 36 weeks gestation). After delivery, postpartum people who have never received Tdap are given a dose (see CDC: Recommended Immunizations for Adults Aged 19 Years and Older, United States, 2025).

Because tetanus can develop after a wound or after an injury that breaks the skin becomes contaminated, people over the age of 7 who have received the Tdap vaccine and have a wound may be given Tdap or Td vaccine to prevent tetanus from developing. People over the age of 7 who have not received the Tdap vaccine and have a wound are given Tdap vaccine.

People who should not receive this vaccine

People who have had a serious, life-threatening allergic reaction (such as an anaphylactic reaction) to any component in the DTaP ar Tdap vaccine should not receive it.

Additionally, people who have any of the following problems should not receive either vaccine:

  • A coma, a decreased level of consciousness, or seizures that last a long time within 7 days after receiving a dose of DTaP or Tdap

  • Seizures or another nervous system problem

  • Development of Guillain-Barré syndrome within 6 weeks of receiving a vaccine that protects against tetanus

  • Severe pain or swelling after a previous dose of any vaccine that protects against tetanus or diphtheria 

Certain other conditions may affect whether and when people are vaccinated (see also CDC: Who Should NOT Get Vaccinated With These Vaccines?).

If people have a temporary illness, doctors usually wait to give the vaccine until the illness resolves.

Side Effects of Diphtheria-Tetanus-Pertussis Vaccine

Most side effects are mild to moderate and can last from 1 to 3 days. They may include the following:

  • Soreness, pain, and redness at the injection site

  • Fever

  • Fussiness

  • Tiredness

  • Loss of appetite

  • Vomiting

Serious side effects are rare. They include the following:

  • A fever of 104.9° F (40.5° C) or higher that has no other cause and appears within 2 days of receiving the vaccine

  • More than 3 hours of severe, inconsolable screaming or crying within 2 days of receiving the vaccine

  • A change in mental state (such as confusion or drowsiness) within 7 days of receiving the vaccine

  • A seizure within 3 days of receiving the vaccine

  • Collapse or shock within 2 days of receiving the vaccine

  • Immediate and severe allergic reaction to the vaccine

The DTaP or Tdap vaccine is not repeated if seizures occur within 3 days after the vaccine is given or other signs of brain malfunction occur within 7 days after the vaccine is given.

Serious side effects usually result from the pertussis component of the vaccine. If they occur, the DTaP or Tdap vaccine is not used again. Instead, the Td vaccine, which does not contain the pertussis component, is used to complete the vaccination series.

For more information about side effects, see the package inserts.

More Information

The following English-language resources may be useful. Please note that The Manual is not responsible for the content of these resources.

  1. Centers for Disease Control and Prevention's (CDC): Tdap (Tetanus, Diphtheria, Pertussis) vaccine information statement

  2. CDC: DTaP (Diphtheria, Tetanus, Pertussis) vaccine information statement

  3. European Centre for Disease Prevention and Control (ECDC): Diphtheria: Recommended vaccinations

  4. ECDC: Tetanus: Recommended vaccinations

  5. ECDC: Pertussis: Recommended vaccinations

quizzes_lightbulb_red
Test your KnowledgeTake a Quiz!
iOS ANDROID
iOS ANDROID
Download the free Merck Manual App iOS ANDROID