Page 107 - Primary Five Science

Artificial immunity / acquired

immunity

A Person gets artificial immunity through vaccination.
Importance of immunization.

 To stay healthy and reduce the chances of early death.

 To live a productive sick free life.

 It strengthens the immune system of the body.

Vaccines

Vaccines are special drugs introduced to the body

to stimulate the body to produce dis-

ease fighting chemicals (antibodies)

Types of Vaccines

There are three types of vaccines namely:

1. Toxoids: (Poisonous substance) There are pre-
pared from toxins produced by bacteria in the body. They are

made harmless and injected into the body.

2. Attenuated: (Weak disease causing germs). These are live

bacteria or virus which have been weakened hat they cannot

cause diseases. E.g. BCG vaccine, measles vaccine, rabies vaccine,
When one gets a disease, the body produces antibodies to fight the
yellow fever vaccine, chicken pox vaccine

3. Dead organism vaccines: (Dead disease causing germs).

carrying organisms. Each group of Anti- These are killed bacteria or virus that has been grown in suitable

host cells. They are made harmless before being injected into a

person e.g. cholera and the sack anti polio vaccine, DPT vaccine,

typhoid vaccine, etc.