Table Of Contents

  Characteristics of a Virus
    - Evolutionary History
    - Vaccines
    - Discovery of the Virus
   Viral Infections
    - The Host
    - How Viruses Infect
    - Types of Infections
    - What's an Infection?
  Beyond Viruses: Viriods
  Virus Research
  Infection Prevention

Scientists say, that viruses have existed since the beginning of life on Earth. Viruses have plagued animals, plants, fungi and protozoa as long as anyone can possibly trace back in time. Even as the years passed, and life evolved from a primitive 'primordial ooze' into more complex vertebrates, viruses maintained their reign of terror. But does this mean that viruses haven't changed at all over the millennia? Of course not. Just as life evolved, developed and adapted to the new and changing environment, so did viruses.

In their humble beginnings, viruses existed primarily as unprotected genetic strands that carried hereditary information from newly developed life to its offspring. They were messengers. Over time the ever-changing environment of Earth influenced many changes in the method of this transfer of information. The genetic messengers evolved as their hosts did, and they eventually developed protective outer casings to protect themselves from the elements. As life became more complex and cells began to self-reproduce, viruses lost their primary function. Cells took over the messenger role, and so viruses began to infect rather than exchange genes with their hosts. Almost seemingly set on revenge, the newly evolved viruses infected every living thing, and proscribed each cell with their own genetic formulas. They became parasites. They were unstoppable.

Continuing to progress, viruses developed the ability to jump from species to species by changing their genetic material to fit the new hosts' bodies. They were determined to survive throughout the centuries no matter the cost of life. The viruses of today are highly complex and elusive. Over their one million plus years on Earth, viruses have developed their own protection, means of survival and efficient ways of infecting their hosts. The medical researchers of today are constantly studying viruses in hopes that we will soon be able to understand them. But fighting viruses is like fighting an enemy who keeps up with every new advancement in weapons technology; the more time they have, the more precocious and powerful they become.


About 200 years ago Edward Jenner might as well have been known as the luckiest man alive. It was in the year 1796 that this country doctor made one of the most astounding discoveries ever. Of course, at the time Jenner didn't know the magnitude of the medical powers he was experimenting with. The experiment Jenner performed would now be considered extremely crude and dangerous. While practicing medicine in the small town of Gloucestershire, England, he decided to experiment with the effects of cowpox and smallpox. Cowpox was a common occupational hazard in the dairy country of England. Coming from sores on the udders of dairy cows, cowpox was a highly contagious disease with caused fever, nauseas and pustular sores on certain areas of the skin. Based only on an old wives' tale he heard as a teenage apprentice -- milkmaids who had been infected with cowpox never became infected with smallpox—Jenner decided to infected his first son with cowpox. A few days later, he infected Ed Jr. with smallpox. His son never got the disease.

With this encouraging result, Jenner decided to infect a young boy, James Phipps, with the contagious material of both diseases. This boy's cowpox infection also healed quickly, and he was back in perfect health after only a short amount of time. Afterwards James was injected with smallpox, but was seemingly unaffected, just like Jenner's son. Although no one at the time understood what exactly had prevented the boy from becoming infected with smallpox, it was certain that this obscure doctor had performed a miracle. Dr. Edward Jenner had discovered the first official vaccine, recorded on the 14th of May 1796. Throughout 1796, cowpox invaded the English countryside, providing Jenner with yet another opportunity to test his promising vaccination theories. He not only began investigating cases of milkers who were protected from smallpox by cowpox, but he also studied other inoculations for diseases such as swinepox and a number of bacterial infections. Jenner went on to publish papers on his experimentation. The paper describing the first discovered vaccination was appropriately titled, "An inquiry into the Causes and Effects of the Variolae Vaccineae, a Disease Discovered in some of the Western Counties of England, particularly Gloucestershire, and known by the name of the Cowpox by Edward Jenner, M.D. F.R.S. & C." Within two years, it was translated into many languages and reprinted all around world. Jenner became famous, but met both good and bad criticism. Newspapers and Magazines mocked his work. They would print cartoons showing vaccinated patients sprouting horns and mooing, with titles like "The Cowpock – or the Wonderful Effects of the New inoculation." Jenner had no idea why the vaccination worked, just that it did, but he spawned the first organized field of viral study. A year before he died in 1823, another great man that would change our view of the world was born.

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