Most side effects of the Tdap vaccine are mild and include redness, pain or swelling in the arm that received the shot, tiredness, mild fever and headache, according to WebMD. Muscle aches, stomach discomfort and swollen glands may also occur. Allergic reactions occur very rarely.
The Tdap vaccine provides immunity against tetanus, diphtheria and pertussis, commonly known as whooping cough. The Centers for Disease Control and Prevention perceives the risks associated with developing any of these three illnesses to outweigh the risks of receiving the vaccine by a substantial amount, according to WebMD. Tetanus, a bacterial infection that infects the body through cuts in the skin, is fatal in one out of five cases. The infection damages the nervous system and produces severely painful muscle spasms, including spasms of the jaw muscles that render the person unable to open the mouth.
Diphtheria makes breathing difficult and can damage the heart and nervous system, while pertussis attacks the respiratory system, potentially causing severe breathing issues, notes WebMD. Both diphtheria and pertussis are highly contagious.
Tdap is given to adults ages 19 and up, while DTaP is the name of a similar vaccine that prevents the same three infections in children, states WebMD. Another booster vaccine called Td is available to provide prolonged protection against tetanus and diphtheria.