The DTP, or what is now the newer DTaP vaccine, provides protection against diphtheria, tetanus, and pertussis. The newest form of DTP is the DTaP (Certiva or Infanrix), which contains an acellular pertussis component that is reported to have fewer side effects than older forms of the pertussis vaccine.

Due to increasing concerns about the amounts of mercury in a stabilizing agent called thimerosal, a new DTP vaccine called Tripedia has been developed. This vaccine has little or no thimerosal and was approved by the FDA in March 2001. In 2002, a new vaccine called PEDIARIX, which contains DTP, polio and hepatitis B, was approved. PEDIARIX only requires 3 shots instead of 9 for protection against these five diseases.

Administration
The DTaP should be administered at 2, 4, and 6 months. A fourth booster should be given anywhere from 15 to 18 months. The fourth dose may be administered as early as 12 months of age, provided six months have elapsed since the third dose and the child is unlikely to return at age 15 to 18 months.

Side Effects
Most reactions to the DTP are minor and usually start in the first 3 days after the booster and do not last long. Most people do not have serious reactions to this vaccine, although there are very rare cases of severe allergic reactions and death that have been reported.

Mild reactions include:

• Sore arm (or leg)
• Acetaminophen or ibuprofen may be used to control pain.
• Do not use aspirin.
• Fever:
• Acetaminophen or ibuprofen may be used to control fever.
• Do not use aspirin.
• Fussiness
• Decreased appetite
• Increased fatigue
• Vomiting

More severe reactions include:

• Non-stop crying for 3 hours or more (100 out of every 10,000 doses)
• Fever of 105 degrees F. or higher (30 out of every 10,000 doses)
• Seizures (6 out of every 10,000 doses)
• Child becomes limp, pale, and less alert (6 out of every 10,000 doses).

The most severe reactions are:

• Severe allergic reactions:
• Difficulty breathing
• Hoarseness
• Wheezing
• Hives
• Pale and sweaty
• Severe weakness
• Fast heart beat
• Dizziness
• Severe brain reaction:
• Prolonged seizure
• Coma
• Decreased level of consciousness