Tetanus, diphtheria, pertussis vaccine (Tdap)

Tetanus is a serious disease that causes muscle contractions, particularly in the jaw and neck muscles. The bacteria that cause tetanus enter the body through cuts or wounds. Severe complications of tetanus infection can be life-threatening.

Diphtheria is a serious infection that usually affects the mucous membranes of the nose and throat. In advanced stages, diphtheria can damage the heart, kidneys and nervous system. Even with treatment, the disease can be deadly, especially in children. Diphtheria is rare in the U.S., thanks to widespread vaccination. But many countries still have high rates of diphtheria.

Whooping cough (pertussis) is a highly contagious respiratory tract infection. It often causes a severe hacking cough followed by a high-pitched intake of breath that sounds like "whoop." Among children, whooping cough mainly affects kids too young to be fully vaccinated and teens whose immunity has faded. The infection can be deadly in infants.

The Tdap vaccine is used to boost a child's immunity to tetanus, diphtheria and whooping cough. Birth mothers get the Tdap vaccine during pregnancy to provide some protection against whooping cough to newborns. The ACIP recommends babies get three doses during their first year, and two additional doses before age 7. After age 18, ACIP recommends everyone get a Tdap, or at least at tetanus vaccine, every 10 years.

The Tdap vaccine uses inactive, weakened versions of the tetanus, diphtheria and pertussis toxins. After vaccination, the body begins building an immune response against these toxins. The Tdap vaccine is 94% to 100% effective in preventing tetanus and diphtheria. Protection lasts about 10 years. The Tdap vaccine is 85% effective in preventing pertussis. Protection lasts 1 to 2 years.

This vaccine shouldn't be given to a child who has:

• A history of an allergic reaction to any previous dose of a vaccine that protects against tetanus, diphtheria or pertussis
• A history of coma, decreased level of consciousness or prolonged seizures within seven days after a previous dose of any pertussis vaccine
• Any severe, life-threatening allergies
• Seizures or another nervous system problem
• A history of Guillain-Barre syndrome
• A history of severe pain or swelling after a previous dose of any vaccine that protects against tetanus or diphtheria