The vaccine that immunizes against pertussis, or whooping cough, also immunizes against diphtheria and tetanus. Called the DTaP vaccine, it is given via injection to infants and children from 6 weeks to 7 years of age. Several side effects are possible.
About one child in four who receives the vaccine develops a fever of 99.5 degrees F or higher. Parents can prevent or reduce the fever by giving the child an aspirin-free pain reliever when the injection is administered, and for the next 24 hours according to directions.
Injection Site Discomfort
Another DTaP side effect experienced by about one child in four is redness, swelling, soreness, bruising or irritation at the injection site. This side effect may last for several days. Again, an aspirin-free pain reliever can reduce these problems.
About one child in 30 experiences swelling of the entire arm or leg that was injected. This occurs more often after the fourth and fifth doses of the DTaP. The swelling can last up to a week.
Other Common Effects
Other common side effects include fussiness, restlessness, tiredness, lack of appetite and vomiting. These effects occur within one to three days after receiving the vaccine.
Serious reactions also can occur, although they are much less likely. These include crying for three hours or more, a fever of over 102 degrees F, and seizures.
Severe allergic reactions have been reported in fewer than one in 1 million doses, and the U.S. Centers for Disease Control and Prevention (CDC) states that they may not actually be related to the vaccine. These reactions result in long-term seizures, collapse, coma and permanent brain damage.