Advertisement
question

Why do people only get some diseases, like chicken pox, once?

Discovery Health
Discovery Health
answer

For many diseases, if you catch them once, you will never catch them again. Measles is a good example, as is chicken pox.

When these diseases make it into your body, they start reproducing. As this happens, the immune system gears up to eliminate the disease. In your body you already have B cells that recognize a virus and produce antibodies for it. But there are only a few B cells for each antibody. Once these few B cells recognize a particular disease, the B cells turn into plasma cells. They clone themselves and start pumping out antibodies. This takes time, but the disease runs it course. Eventually, the disease is eliminated.

While it is being eliminated, however, more B cells that recognize the disease clone themselves but do not generate antibodies. This set of B cells can remain in your body for years. Therefore, if the disease reappears, your body is able to get rid of it before it can do anything to you.

This is how vaccines work. A vaccine is a weakened form of a disease (either a killed form of the disease, or a similar but less virulent strain). Once the vaccine is inside your body your immune system mounts its defense, but because the disease is different or weaker the body shows no symptoms of the disease. When the real disease invades your body, the immune system is able to eliminate it immediately. Vaccines have been made to combat all sorts of diseases, both viral and bacterial.

Continue Learning about Chicken Pox

How long does chickenpox usually last?
Chickenpox will probably stick around for more than a week. Learn more from our experts about chicke...
More Answers
Could I have chickenpox and not even know it?
You may not know you have chickenpox after you have first been infected with it. Learn why.
More Answers
Will a bath spread a chickenpox rash?
Baths don't cause a rash from chickenpox to spread over your body. Learn more from our contributors....
More Answers
Can my child go to school if he or she has chickenpox?
Most schools will require your child to stay home for at least a few days.
More Answers

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.