Science & Technology in Action

7th Edition

The Evolution of Vaccines


The immune system is critical to our ability to resist disease. This lesson deals with the topic of vaccines. It relates how vaccines are evolving and describes different types of vaccine. Some first and second generation vaccines are identified. The lesson describes how third generation vaccines are still at an experimental stage.
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Lesson excerpt

Vaccines Old and New

It is widely believed that the story ofvaccination began with Edward Jenner, but it had, in fact, started nearly a millennium earlier when people in India, China and Africa deliberately exposed themselves to milder strains of a disease in order to protect themselves against the more virulent forms of the disease.

The Jenner story has many forms but essentially he noticed that milkmaids who had contracted cowpox, a mild disease, did not suffer from smallpox. In 1796 he purposely infected a young local farm boy by putting the pus from a cowpox sore into two small cuts he had made on the boy's left arm. When the boy recovered from the cowpox he was then deliberately infected with smallpox and fortunately he did not contract the disease. The immunisation did not always work and many people were afraid and tried to make a fool of Jenner and immunisation using cartoons showing people growing parts of cows. Luckily immunisation did work often enough for the idea to eventually catch on.

Vaccination is derived from the Latin "vaccinus" meaning "of or from cows". In the late 1800's Louis Pasteur built on this foundation and produced vaccines against chicken pox, cholera, anthrax and then rabies. Although he knew vaccination worked he did not know how. The process of administering the vaccine is calledinoculation.

How do Vaccines Work?
Vaccination works by activating the body's natural defence systems to produce immunity that is, the ability resist a particular disease when exposed to it, or at least limit it to a mild form. The majority of vaccinations are for viral diseases but some are used to treat and prevent cancers, to treat snake bites, and are even being developed to help treat addictions.

True or False?

  1. Smallpox does not exist as a disease any longer. true
  2. Only humans can be given vaccinations. false
  3. Vaccination is always successful. false
  4. Vaccines can prevent certain cancers. true
  5. The BCG vaccine is used to treat a bacterial disease. false
  6. Tetanus injection will protect you for life. false
  7. The process of administering a vaccine is called inoculation. true
  8. The presence of adjuvants makes vaccines less efficient. false
  9. Antigens are produced by the body in response to the presence of a foreign organism.
  10. A pathogen is a disease causing organism. true