Re: Why does the common cold mutate so rapidly? How does it do this?

The common cold is caused by over 180 different viruses. Just like there are different kinds of things to write with, such as crayons, markers, pens, and pencils, there are different kinds of viruses. Some of these are more common than others.

     So just what viruses cause colds:
     75% of colds are caused by rhinoviruses
     15% of colds are caused by coronaviruses
     10% of colds are caused by other viruses.

What is a serotype? A serotype means a type that the body can recognize as different, and thus genereate a new response to. Each virus is like a crayon - there are hundreds of different colors that each have their own name, and that you recognize with your eyes, as different even though they are the same thing, a crayon.

What is this response your body has? Your body, in order to make you feel better, has to remove these viruses. It does this by capturing them with certain cells and destroying them. Once they are destroyed your body gets better. This response is specific to each virus, and that way this virus can't make you sick again.

Even if you caught two colds a year you would have to live to be well over fifty years old just to run out of rhinoviruses, not to mention the other viruses that can cause colds too.

What is a virus? A virus is made up of two things, a protective coat made of protein, and a strand of nucleic acid. This nucleic acid is like a recipe, it allows the virus to make more viruses, which in turn makes you sick. There are two different kinds of nucleic acid, DNA and RNA. A virus can contain either DNA or RNA.

In order to make new viruses the virus must copy its nucleic acid, it needs to copy the recipe, and put it in a protective coat, just like a winter coat protects you from bad weather. When DNA is copied the virus is very careful to make sure that it copies itself correctly. It has a built in spell checker to make sure it doesn't make any mistakes. Since it has a built in spell checker it changes very slowly, because it only rarely misses a mistake.

Cold viruses though have nucleic acid made of RNA.This allows the virus to change faster. It does this because an RNA virus does not have a built in spell checker and so it makes quite a few mistakes. These mistakes are called mutations, and when the virus has made enough mistakes it becomes different, or a new serotype.

Just like in that word game where you change only one letter at a time to generate a completely different word:

soak
soar
sear
pear
peer