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What is in Those Vaccines: Part III?

© Neal Rolfe Chamberlain

This is DTaP week. Last week I said that I would tell you what is in the DTaP vaccine and what diseases are prevented by this vaccine. DTaP stands for Diphtheria, Tetanus (Lockjaw), and Acellular Pertussis (Whooping cough). Two of these diseases, diphtheria and pertussis, at the beginning of the 1900's killed literally thousands of children in the world each year. Tetanus was also a dreaded disease that could frequently cause death in people of any age.

Diphtheria is a disease caused by a bacterium called Corynebacterium diphtheriae.  This particular bacteria can grow in our throats and produces a protein that can kill the cells that line our throats. When enough cells die a membrane can close off the throat and choke a person to death. More commonly the toxin from this bacterium would go to a person's heart and damage it. If the damage was severe enough the heart would stop and the person would die. The vaccine given to our infants at 2, 4, 6, 15-18 months, and at 4-6 years of age contains the toxin from this bacterium. However, so that the toxin doesn't cause any damage to the child's body it has been inactivated by chemical treatment. Toxins that have been inactivated are called toxoids. In other words the diphtheria toxoid still causes our body to make antibodies to the toxin but does NOT cause any damage to the cells of our body. As a result, when our body sees the active diphtheria toxin the antibodies in our body will destroy it before the toxin starts killing our cells.

Pertussis is caused by a bacterium called Bordetella pertussis. This bacteria can also grow in our throats and it can get down into the lung passageways called the bronchi. Once in the bronchi it produces toxins that cause the cells that line the bronchi to die and then fall off and partially plug up the bronchi. When this happens our lungs instinctively want to clear this plug of dead cells. To do this the person will cough. The person will cough and cough and cough and cough and cough and cough. These coughing spells can last up to 2-3 minutes. Then the person will need air and rapidly inhale causing a whooping sound. To hear what such a coughing spell sounds like click here. In the old days (1998 and older) we used to vaccinate children with killed whole Bordetella pertussis cells. Unfortunately, this vaccine was reported to have caused some severe side-effects. The debate on whether these reports were true or not is really not relevant because the new vaccine no longer contains these bacterial cells. Researchers

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