What is the DTaP vaccine?

Definition

The DTaP
vaccine protects against three different bacterial illnesses. The
first disease, diphtheria, is caused by the bacterium
Corynebacterium diphtheriae. Infection with this bacterium
causes a severe sore throat and difficulty breathing and swallowing. The second
disease, tetanus, is caused by the bacterium Clostridium
tetani and leads to what is commonly referred to as lockjaw. This
disease causes intense muscle contractions and can interfere with breathing. The
last disease, pertussis, or whooping cough, is caused by the
bacterium Bordetella pertussis. This bacterium produces a severe
persistent cough with a characteristic whooping sound on inspiration between
coughing fits and can lead to respiratory failure.

Mechanism of Action

The vaccine incorporates the three toxins that are produced by
the bacteria in their inactivated forms (known as toxoids).
These toxoids are then administered, leading to an immune response without
actually causing the disease, therefore providing protection from future
illness.

History

Individual vaccines against diphtheria, tetanus, and pertussis were first developed in the late nineteenth and early twentieth centuries. The combination vaccine that incorporated all three was first licensed in 1948. The vaccine was further modified in 1991 in response to a high rate of side effects thought to be caused by the original whole-cell pertussis component. A new, acellular pertussis element was developed at that time and has resulted in a significant decrease in the side effect profile of the vaccine. The DTaP vaccine can be found as a component of combination vaccines such as Pediarix (with hepatitis B and inactivated poliovirus) and Pentacel (with Haemophilus influenzae type B and inactivated poliovirus).

Administration

Health experts recommended that children receive the DTaP vaccine at age two, four, six, and fifteen to eighteen months and again between the age of four and six years. Adolescents and adults should then receive one administration of the Tdap vaccine, which differs from the DTaP in that it contains less of the diphtheria and acellular pertussis components. After the Tdap, adults should receive the Td booster immunization against tetanus and diphtheria every ten years.

Impact

The impact of the DTaP vaccine on public health has been enormous. Diphtheria has been nearly eradicated in the United States, and the incidence of tetanus and pertussis has been greatly reduced. However, of the three diseases, pertussis continues to affect many adults and children in the United States, with morbidity and mortality rates rising among infants.

Bibliography

Advisory Committee on Immunization Practices. “Recommended Adult Immunization Schedule: United States, 2010.” Annals of Internal Medicine 152 (2010): 36-39.

Centers for Disease Control and Prevention. “Recommended Immunization Schedules for Persons Aged 0-18 Years—United States, 2008.” Morbidity and Mortality Weekly Report 57 (2008): Q1-Q4. Also available at http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5701a8.htm.

Harvey, Richard A., Pamela C. Champe, and Bruce D. Fisher. Lippincott’s Illustrated Reviews: Microbiology. 2d ed. Lippincott Williams and Wilkins, 2006.

Loehr, Jamie. The Vaccine Answer Book: Two Hundred Essential Answers to Help You Make the Right Decisions for Your Child. Naperville, Ill.: Sourcebooks, 2010.

Pan American Health Organization. World Health Organization. Control of Diphtheria, Pertussis, Tetanus, “Haemophilus influenzae” Type B, and Hepatitis B Field Guide. Washington, D.C.: Author, 2005.

Playfair, J. H. L., and B. M. Chain. Immunology at a Glance. 9th ed. Hoboken, N.J.: Wiley-Blackwell, 2009.

Plotkin, Stanley A., Walter A. Orenstein, and Paul A. Offit. Vaccines. 5th ed. Philadelphia: Saunders/Elsevier, 2008.