What Is Tdap Vaccine?

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What Is Tdap Vaccine?

The Tdap vaccine protects against a disease called pertussis (whooping cough), as well as tetanus and diphtheria. It is recommended for adolescents and adults, and is especially important for pregnant women during each and every pregnancy as it protects the new baby.

Diseases Tdap Prevents

Tetanus, diphtheria, and pertussis are all caused by a bacterium which, if left untreated, can cause serious illness and death.


Tetanus, called "lockjaw," causes muscle tightening, especially of the head and neck. This muscle tightening makes it difficult to open the mouth, swallow, and breathe. Tetanus enters the body through cuts or wounds.

Tetanus is not common the United States, with an average of 30 reported cases each year. Among those who do get it, most either never got a tetanus vaccine or did not complete the schedule of shots, according to the Centers for Disease Control (CDC).


Diphtheria is a type of bacteria that causes an infection that coats the mouth and throat, and potentially can affect breathing and/or cause harm to other organs from bacteria-produced toxins.

Symptoms of diphtheria appear two to five days after exposure and may include:

  • Damage to the heart, kidneys, and nerves (if the bacteria enter the bloodstream)
  • Fever
  • Swollen lymph nodes
  • Thick, gray coating in the nose or throat
  • Weakness


Pertussis is a highly contagious disease spread by coughing, sneezing, or simply being in the same airspace for an extended time. In the last 20 years, rates of pertussis have been rising in very young infants who don't yet have their immunizations and in adolescents and adults. Pertussis is especially serious for infants under age 1, and can even be fatal.

Symptoms of pertussis appear within five to 10 days of exposure and may include:

  • Apnea (gaps in breathing)
  • Fatigue
  • High-pitched "whooping" cough lasting two weeks or more
  • Low-grade fever
  • Pneumonia
  • Spells of coughing and choking that make breathing difficult
  • Vomiting

Types of Tdap Vaccine

There are two Tdap vaccines approved by the FDA: Adacel and Boostrix, which include the tetanus toxoid (T), reduced diphtheria toxoid (d), and acellular pertussis (ap) vaccine in a single shot.

According to the CDC, the upper-case letters (”T” in Tdap) mean the vaccine has full-strength doses of that part of the vaccine, while the lower-case letters (“d” and “p” in Tdap) mean the vaccine contain smaller doses.

Like most newer vaccines, Tdap vaccines are preservative-free, which means they do not contain thimerosal. They are made with reduced quantities of the same antigens that are in the Infanrix DTaP vaccine that many kids already get.

Who Needs a Tdap Vaccine?

According to the CDC, the Tdap vaccine is currently recommended for the following:

  • Kids between ages 7 and 10 years who were not fully vaccinated with other whooping cough vaccines, like DTaP
  • Kids between ages 11 to 18, with preferred administration at ages 11 through 12 years
  • Adults ages of 19 and older as a one-time dose, followed by a Td or Tdap booster every 10 years
  • Pregnant women between 27 and 36 weeks of each pregnancy (getting the vaccine during the third trimester provides antibodies to protect the baby until they can receive the childhood version of the shot—called DTaP—at 2 months old)
  • Seniors over the age of 65 if they are going to have close contact with a newborn or infant less than 12 months of age
  • Healthcare professionals who have not previously received Tdap and who have direct patient contact

You should notify your doctor and possibly avoid the Tdap vaccine if:

  • You've had a past allergic reaction to any of the vaccine ingredients, especially those in the tetanus vaccine.
  • You experienced a coma or seizures within a week after receiving DTap, the childhood vaccine for pertussis.
  • You have a latex allergy (although you may be able to receive the shot via a latex-free vial or syringe).
  • You have a history of seizures, epilepsy, or Guillain-Barré syndrome.

How Effective Are Tdap Vaccines?

The pertussis portion of the Tdap vaccine doesn't work as well as experts would like; the immune protection seems to wane fairly quickly. However, overall, the vaccine is effective and strongly recommended.

According to the CDC, the vaccine protects:

  • 95 in 100 people from diphtheria for approximately 10 years
  • Almost everyone from tetanus for roughly 10 years
  • Roughly 7 out of 10 people from whooping cough in the first year after getting Tdap, and three or four in 10 people four years after getting the shot

Preventing Pertussis

In addition to getting your Tdap vaccine, the CDC recommends practicing good hygiene to prevent pertussis, including:

  • Covering your mouth and nose with a tissue when you cough or sneeze, or coughing into your upper sleeve or elbow if you don't have a tissue
  • Washing your hands often, for at least 20 seconds, with soap and water
  • Using an alcohol-based hand sanitizer if you don't have access to soap and water

Side Effects

Tdap vaccine side effects, which are typically mild and resolve on their own within a few days, may include:

  • Body aches
  • Chills
  • Diarrhea, nausea, or vomiting
  • Fatigue
  • Fever
  • Headache
  • Loss of appetite
  • Joint pain
  • Pain, redness, or swelling at the injection site
  • Rash
  • Swollen glands

If these symptoms become severe or persistent, contact your healthcare provider immediately.

History of Tdap Vaccine

Vaccines that provide protection against tetanus, diphtheria, and pertussis aren't new. The original DTP vaccine, after all, had been around since 1948, and DTaP since 1997. And before those combination vaccines, we had individual vaccines against each of these vaccine-preventable diseases. The Tdap vaccine first became available in 2005, and was the first to include pertussis protection for older kids and adults.

A Word From Verywell

The Tdap vaccine can be one of the best preventive measures a parent can take to protect against whooping cough, tetanus, and diphtheria. Talk to your healthcare provider today to make sure you and your family are up to date.

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6 Sources
Verywell Family uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Centers for Disease Control and Prevention. Tetanus. February 28, 2019.

  2. Centers for Disease Control and Prevention. Pertussis: Summary of vaccine recommendations. January 2020.

  3. Centers for Disease Control and Prevention. Diphtheria. December 17, 2018.

  4. Centers for Disease Control and Prevention. Pertussis (whooping cough). November 18, 2019.

  5. Centers for Disease Control and Prevention. Epidemiology and prevention of vaccine-preventable diseases, 13th Edition. Updated May 2019.

  6. Centers for Disease Control and Prevention. Pertussis frequently asked questions. November 2019.