Pam Saunders, Age 12, of Hopewell, Va., for her question:
What exactly are viruses?
Viruses are the bandits of the world of microbes. They cause at least 50 of the diseases that attack us, and no one can find anything kind to say about these midget germs. The wonder drugs cannot harm them, but medical scimce has other methods to protect us from some of the viruses. Our bodies also can defend themselves against some virus attacks.
Every virus is a parasite, unable to make a living for itself. It depends upon the living cell of a plant or animal. Some of the miniature bandits attack our bodies, others attack plants or microscopic bacteria. The size of a virus is measured in millimicrons. The micron unit is one millionth part of a meter, and the Milli micron is one thousandth part of a micron.
These midgets are too small to be seen through ordinary microscopes, but they can be photographed with the electron microscope. Hence, we know that some are shaped like sausages and some look like sticks. others are round balls, and others look like squirmy tadpoles. In Size, they range from 15 to 450 millimicrons almost a million of them to the inch.
The average virus is a small wad of nucleic acids packed inside a thin shell of protein. Nucleic acids are the vital chemicals in all living cells. In our own bodies, the miraculous nucleic acids DNA and RNA direct the vital processes of life.
An invading virus can challenge the nucleic acids within a cell and force it to issue different directions. Instead of tending to its own duties, the invaded cell is forced to produce more viruses like the attacking parasite. These newcomers then spread to infect more cells. The body may be able to build tiny antibodies or other weapons against the teeming enemy, but this takes time.
We can be infected with the mumps virus only once. The weapons the body builds against the first attack stay in the body for life. Vaccines are controlled doses of mild virus infections. They coax the body to prepare for deadly attacks by building defenses in advance. Medical science offers us vaccines to protect us from the worst ravages of the polio and smallpox viruses.
Viruses arc the crue1 gems that cause rabies among wild and domesticated animals. If you have a dog, you will surely have him vaccinated to protect him from the misery of virus which causes distemper. Other viruses attack and destroy plants. The first virus to be discovered was the tobacco mosaic which destroys the leaves of the tobacco plant with rashes of withered brown spots.