Question

What is vaccination? Mention the four ways in which vaccines are prepared, giving the name of one disease for which each type of vaccine is used.

Answer 1

1. Vaccination is the practice of artificially introducing germs into the body for developing resistance to particular diseases.

A vaccine can be prepared by any one of the following four methods:

Using killed germs:

TAB vaccine for typhoid, salk's vaccine for poliomyelitis are prepared through it.

Using living weakened germs:

1. The living germs are treated in such a way they become very weak and cannot cause the disease.
2. They can induce antibody formation in the body e.g, Measles.

Using fully virulent living germs:

1. These virulent germs in small doses are introduced into the body as vaccine.
2. These produce antibodies in the body.

Using Toxoids:

1. Toxoids are prepared from the extracts of toxins which are secreted by bacteria.
2. These are poisons and made harmless by adding formalin into them.