No longer is death by small pox, debilitating pain from polio, death or serious illness from measles, mumps and rubella a constant danger. Through a series of scheduled vaccinations, a child is protected against diseases once capable of wiping out millions of people.

Diseases are usually caused by one of two organisms, bacteria or a virus. A bacterial infection can usually be treated with antibiotics, but viruses don't respond to antibiotics and often the only treatment is to let them progress until the body produces antibodies.

For some conditions this doesn't happen early enough and the result is crippling paralysis or death. One way to help overcome these viruses is to create the antibodies before contracting the disease and this is done by way of a vaccine.

The vaccine is created from a modified strand of that particular disease. The vaccine works its magic by letting the immune system conquer and build up a resistance to the disease. Once that has happened, then the immune system is protected from the deadlier strands. Think of it as the same type of protection a computer program can offer against outside attackers.

A vaccine is a version of a specific disease. Take for example small pox. There was the terrible version of the small pox that ravaged the world, and there was a much milder version that infected cows.

Jenner noticed that milkmaids and farmers who contracted the cowpox did not come down with small pox, even when exposed. He tested this theory on a child by injecting him with cowpox. Once the boy recovered, Jenner then exposed him to smallpox.

The result was astounding to Jenner and the world. If a person were infected with a disease or a milder variety of disease, then the body built up immunity and would not be affected again.

Edward Jenner's discovery of vaccines and his work with small pox have changed the medical world as we know it. The world does not have to isolate itself any longer from other communities for fear of disease and possible death. Houses are no longer marked with signs of plague.

The only recognizable sign of Jenner's battle is a shot record that shows what immunizations a child has received. There are still diseases that currently do not have a vaccination, but there will come a time in the future when even those are nothing more than a stamp on a card.