Infants and young children get vaccinated with the DTaP vaccine to protect them from diphtheria, tetanus, and pertussis. However, as children get older, the protection from the DTaP shots starts to wear off. The Tdap vaccine is the booster shot that helps protect preteens/teens and adults from the same diseases that the DTaP vaccine protects young children from.

Pertussis, also known as whooping cough, is still common in the United States, and outbreaks still occur. Recently between 10,000 and 50,000 cases have been reported each year.

The CDC recommends that all preteens get one dose of Tdap when they are 11 or 12 years old. Teens and adults who did not get the Tdap vaccine at that age should get it as soon as possible. Tdap is especially important for anyone who is in close contact with a baby younger than 12 months of age.


Commonly known as lockjaw, tetanus is a severe disease that causes stiffness and spasms of the muscles. Unlike other vaccine-preventable diseases, which are transferred from person to person, tetanus bacteria are found in places such as dirt, dust, and manure, and can therefore never be eradicated. The bacteria enter the body through any break in the skin, such as a cut or a puncture wound. A person can also be infected after a burn or animal bite.

There’s no cure for tetanus. Treatment focuses on managing complications until the effects of the tetanus toxin resolve. Deaths from tetanus occur most in people who haven’t been immunized.

Learn more about tetanus.


Diphtheria is a serious bacterial disease that can be spread from an infected person by coughing and sneezing. Diphtheria can also be spread by contaminated objects or foods.

Once infected, toxins, which are caused by the bacteria, can spread through the bloodstream to other organs and cause significant damage including injury to the heart, kidneys and other organs. Nerve damage and paralysis can also result.

Learn more about diphtheria.


Pertussis, also known as whooping cough, is a highly contagious respiratory disease that spreads easily from person-to-person through coughing and sneezing. It can cause a severe hacking cough that and may be followed by a high-pitched gasp for breath that sounds like a “whoop.”

People of all ages can be affected by pertussis; however, pertussis can be particularly dangerous, and even deadly, for infants under 12 months of age. Babies often get whooping cough from their older brothers or sisters, or other people in the family.

Preteens and teens with pertussis may have prolonged coughing spells that last for weeks or months. However, the “whoop” sound may not be there and the illness is generally less severe than in young children, especially in those who were previously vaccinated against whooping cough. In fact, some adolescents and adults who get pertussis may not even know they have the disease.

Learn more about pertussis