Medical Health Encyclopedia

Immunizations - Diptheria, Tetanus, and Pertussis

(Page 5)




Neurologic Effects in Pertussis Component. Of concern have been a few reports of permanent neurologic abnormalities that have occurred after children have been vaccinated. Such reports include attention deficit disorder, learning disorders, autism, brain damage (encephalopathy), and even death.

It is well known that the diphtheria and tetanus components cause no adverse neurologic effects, so some people suspect the pertussis component. However, many major studies, including an important statistically sound analysis in 2002, found no causal relationship between neurologic problems and the pertussis vaccination. In fact, one study indicated that children who received pertussis vaccine had fewer problems in school than those who were not vaccinated, regardless of family income levels. Studies on the newer DTaP have reported no safety concerns to date.




There may be some exceptions. Studies now suggest that in cases where neurologic problems have been strongly linked to the vaccination, high fevers -- not immunization -- are responsible. Children with known neurologic abnormalities may also be at risk for an outbreak of symptoms two or three days after the vaccination. Such a temporary worsening of their disease rarely poses a danger to the child. (Some experts suggest that children who have new neurologic events following their shot may already have a preexisting impairment, such as epilepsy, which is revealed -- but not caused -- by the vaccine.) To date, there is no proof that the pertussis vaccine causes these neurologic events, which, in any case, are so infrequent as to be nearly statistically unmeasurable.

Important Note: Unwarranted fears of side effects from vaccinations can be dangerous. In England such fears have caused a significant decline in immunization rates since the 1970s. Outbreaks of whooping cough have occurred as a result, causing a number of deaths and brain damage in many children. Small babies are particularly endangered if they become infected from older unvaccinated children (who usually have a mild disease).

Symptoms of Severe Reactions to Vaccinations

Call the doctor immediately if a child has any of the following symptoms.

  • Extremely High Fever. A rectal temperature of 105°F or higher. (Temperatures taken under the arm or by mouth often register lower than actual temperatures.)
  • Inconsolable Crying. The child has been crying for over 3 hours without stopping or has a cry that isn't normal, such as being high-pitched.
  • Convulsions. The child's body starts shaking, twitching, or jerking. This is usually in response to a high fever. Place the child face down with the head to one side, protecting the head from hitting anything hard. Be sure the child can breathe freely. Seizures caused by fevers usually last less than 15 minutes.
  • Shock. The child collapses, turns pale, and becomes unresponsive.
  • Severe Allergic (Anaphylactic) Reaction. Swelling in the mouth and throat, wheezing and breathing difficulties, dizziness. The child collapses or is pale and limp.

Call the doctor if the following symptoms persist for more than 24 hours:

  • The injection site is still red and tender.
  • Fever does not go down.
  • The child is still fussy.


Review Date: 02/14/2007
Reviewed By: A.D.A.M. Editorial: Greg Juhn, M.T.P.W., David R. Eltz, Kelli A. Stacy; previously reviewed by Harvey Simon, M.D., Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital (8/23/2006).

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org).

Find a Therapist
PR Newswire