The DTaP vaccine is a combination vaccine that protects children ages 6 and under against 3 different infections: diphtheria, tetanus, and pertussis (whooping cough).

All three infections can cause serious complications. The Tdap vaccine, given to adolescents and adults, protects against the same diseases.

Here’s what to know before your child gets the DTaP vaccine.

What Is the DTaP Vaccine?

The DTaP vaccine is a combination vaccine that protects children ages 6 and under against diphtheria, tetanus, and pertussis. It’s delivered via intramuscular injection.

An earlier version of the vaccine, known as the DTP vaccine, was developed in the 1940s. It was one of the first combination vaccines in medical history.

While the combination vaccine was effective, some parents and patients rejected it due to its side effects. 

Scientists responded by creating a safer version of the vaccine. Unlike the whole-cell DTP vaccine, the DTaP vaccine uses an acellular version of the pertussis toxin – that is, only one part of the bacterium instead of the whole cell.

Today, the DTP vaccine is no longer used in the United States. 

The DTaP vaccine has far fewer side effects and effectively protects children from three dangerous infectious diseases.

Tetanus

Tetanus is an infection caused by Clostridium tetani, a type of bacteria that usually enters the body through open cuts or wounds. The toxins produced by the bacteria cause highly painful muscle contractions.

Tetanus is sometimes called “lockjaw” because it can “lock” a person’s jaw and mouth, making it difficult to swallow and breathe.

Diphtheria

Diphtheria is caused by a toxin-producing bacteria known as Corynebacterium diphtheria. Symptoms appear two to five days after exposure and may include:

Swollen lymph nodes Fever Weakness Fatigue A thick, gray coating in the nose or throat

If bacteria get into the bloodstream, it can lead to heart, kidney, and nerve damage, as well as paralysis, heart failure, and death.

Pertussis (Whooping Cough)

Pertussis, also known as whooping cough, is a contagious respiratory disease caused by the bacterium Bordetella pertussis.

Symptoms include uncontrollable coughing fits, leading to a “whooping” sound when someone tries to breathe. Serious cases can lead to pneumonia.

While pertussis can affect anyone at any age, it is potentially fatal for babies under 1 year old.

DTaP vs. Tdap

The Tdap vaccine, like the DTaP vaccine, protects against diphtheria, pertussis, and tetanus. However, it’s given to children 7 years and older, adolescents, and adults.

The Tdap vaccine is recommended by the Centers for Disease Control and Prevention (CDC) for:

Adolescents, usually at age 11 or 12, as a booster shotChildren ages 7 or older who haven’t completed the DTaP seriesHealthcare professionals with direct patient contactAdults who have never received TdapAdults, every 10 years, as a booster shot (or every five years after a serious wound or burn)Any adult in close contact with a babyPregnant women during every pregnancy, preferably early in the third trimester

DTaP During Pregnancy

Because pertussis is so dangerous for young babies, the CDC recommends that women get one dose of the Tdap vaccine during pregnancy. Protective antibodies are passed down to the baby, which can protect them from whooping cough early in life. 

It’s best to get the Tdap vaccine during the third trimester, ideally between 27 and 36 weeks.

This can reduce the risk of whooping cough to a young baby by up to 78%.

Side Effects

Side effects of the DTaP vaccine are usually mild. They can include:

Redness, swelling, or tenderness at the injection site Fussiness Fatigue Decreased appetite Nausea and vomiting Fever

In rare cases, the entire vaccinated arm or leg may swell temporarily. 

More serious side effects that can happen after any vaccine include:

Very rarely, a serious allergic reaction Fainting or dizziness Severe pain in the injection site

Cost

The cost of a DTaP vaccine will vary based on your healthcare provider. Most insurance plans are required to provide vaccines at no cost to you.

In the United States, children under 19 can get all recommended vaccinations for free through the federal Vaccines for Children program. Your child qualifies for this program if they’re:

UninsuredUnderinsuredMedicaid-eligibleNative American or Alaska Native

State health departments and federally funded health centers may also provide the DTaP vaccine at low or no cost.

Vaccination Schedule

According to the American Academy of Pediatrics (AAP), your child should get five doses (including three doses for babies and two booster shots for children) of the DTaP vaccine, usually at the following ages:

2 months 4 months 6 months 15-18 months 4-6 years

Who Gets It

The DTaP vaccine is safe for the majority of babies and children. However, the vaccine might not be safe for your child if they:

Are severely allergic to an ingredient in the DTaP vaccine Had a severe allergic reaction after a previous dose Are moderately or severely ill

If your child was diagnosed with a brain or nervous system disease less than a week after a previous DTaP dose, your healthcare provider might recommend a DT vaccine instead.

The DT vaccine protects against diphtheria and tetanus but not whooping cough.

Talk With Your Healthcare Provider

Before getting the DTaP vaccine, you should talk to your healthcare provider if your child:

Had a high fever, a seizure, or uncontrolled crying after a previous dose of DTaP Ever had Guillain-Barré Syndrome Had severe swelling or pain after a dose of a vaccine containing tetanus or diphtheria Isn’t feeling well Is allergic to any component of the vaccine or has ever had an allergic reaction to a DTaP dose

Summary

The DTaP vaccine protects children ages 6 and under from three common, potentially dangerous childhood infections: diphtheria, tetanus, and pertussis (whooping cough). Children should get five doses of the DTaP vaccine, usually at 2 months, 4 months, 6 months, 15-18 months, and 4-6 years. Side effects from the DTaP vaccine are usually mild.

The TDap vaccine protects against the same infections and is given to children ages 7 and older, as well as adults. Pregnant women should get one dose of the TDap vaccine during pregnancy.

A Word From Verywell

The DTaP vaccine is an important way to protect your child from three potentially serious or even fatal infectious diseases. Talk to your healthcare provider about your child’s immunization schedule. If your child has already missed a dose, they can still get up to date to protect them against diphtheria, tetanus, and whooping cough.