Tetanus, Diphtheria, Acellular Pertussis (“Tdap”) Vaccine

What is the Tetanus, Diphtheria, Acellular Pertussis (“Tdap”) Vaccine?

The Tdap vaccine is designed to protect adolescents and adults from tetanus, diphtheria, and pertussis.  Tdap is not a routine pediatric vaccine. If you are interested in learning more about that vaccine, please see our DTaP page.  Tdap is routinely given at age 11 or 12.  The Td vaccine is similar, but only protects against tetanus and diphtheria.  It is recommended as a booster every ten years.

Tetanus, also known as lockjaw, affects the central nervous system causing painful muscle tightening, stiffness and contractions.  While it can affect all of the muscles in the body, it is mostly known for tightening the muscles in the neck and jaw making it difficult to breathe, talk or chew food – thus “lockjaw.”  Other symptoms related to loss of muscle control associated with tetanus include painful body spasms, drooling, excessive sweating, fever, irritability, and uncontrolled bladder and bowel movements.

Diphtheria is a bacterial upper respiratory tract infection which can cause a thick, often gray-colored coating to form in the back of the throat, typically around the tonsils.  This membrane can block the airway leading to difficulty breathing. People suffering from diphtheria often have a swollen neck, also known as a “bull neck,” caused by swelling of the lymph nodes.  Other symptoms include mild fever, hoarseness of voice and nasal discharge.

Pertussis, like diphtheria, is a bacterial respiratory tract infection which causes a thick mucus to form in the airways leading to a persistent cough.  The defining characteristic of pertussis is a high-pitched “whoop” noise during the next breath of air after a cough – thus “whooping cough.”  In adults, the whoop is not as pronounced as in children and diagnosis is typically based on an uncontrollable cough, along with other symptoms including vomiting, weight loss, incontinence, rib fractures, nasal congestion, sneezing, red eyes and mild fever.

Who should receive the Tdap vaccine?

As a booster shot for adults younger than 65 years old, the CDC generally recommends administration of the Td vaccine once every ten years. However, it is also recommended that one of the ten-year Td booster shots be replaced with a Tdap vaccine for people who have not previously received a Tdap shot.

There are other specific recommendations by the CDC for special circumstances in which the Tdap shot should be administered.  A three-dose series of Tdap vaccines is recommended for adults who have an incomplete or unclear tetanus, diphtheria and pertussis vaccination history. Furthermore, Tdap is recommended for pregnant women at least 20 months into gestation, adults who anticipate being in close contact with infants and women immediately following pregnancy if they were not vaccinated during pregnancy.  There are other specific Tdap vaccine recommendations for children ages 7 to 10 and adolescents ages 11 to 18, who did not complete the full childhood tetanus, diphtheria and pertussis schedule.

How is the Tdap vaccine administered?

Before receiving a Tdap/Td vaccine, you should know how it should be administered.  The CDC offers guidelines as to how vaccines should be administered.  All Tdap/Td vaccines should be administered intramuscularly, through the skin, underneath the fatty tissue and into the muscle tissue.  They should always be injected at a 90-degree angle into the deltoid muscle (in the upper arm).  If an intramuscular Tdap or Td shot is injected too high on the arm it can result in a serious shoulder injury.

Tdap links:
CDC Vaccine Administration guidelines
CDC Vaccine Information Statement
Children’s Hospital of Philadelphia – Tetanus Information Summary