Figure 5.34: Eosinophils are important in controlling the allergic reaction.Vaccination is the most effective method of eradicating infectious diseases. It has resulted
in the eradication of smallpox throughout the world and has greatly reduced diseases such
as polio, measles and tetanus. Vaccination involves injecting components of the infectious
agent in a non-toxic form in order to stimulate an individual’s adaptive immune system.
An immune response is produced against the vaccine, resulting in the production of T-
lymphocyte memory cells. When a repeat infection occurs, the body is able to mount an
effective and rapid immune response due to the presence of memory cells.
Figure 5.35: A vaccination campaign in the US.- Antibiotics
Antibiotics are another example of a biotechnological advance in medicine. Antibiotics stop
or inhibit the growth of certain disease-producing bacteria. These substances were originally
found in organisms such as fungi and can now be chemically manufactured. Antibiotics can
be administered to patients intravenously as injections, or in the form of tables, syrups or
suspensions.
Figure 5.36: Antibiotics.- Blood transfusions
Chapter 5. Plant and animal tissues 145