Unit One Nature of the Immune System
I. Introduction and Historical Concepts
Terry Kotrla, MS, MT(ASCP)BB
Introduction
Immunology is a relatively new field.
 Entire history recorded in the last 100
years.
 1960s cells of immune system identified
and characterized.
 Tests developed to detect presence of
immune substances in the blood.

What You Need To Know
Immunity
Immunology defined as the study of the
reaction of a host when foreign
substances are introduced into the body.
 Antigen is the substance recognized as
foreign to the body which causes an
immune response.
 Immunity is the condition of being
resistant to infection.
 Serology is the study of the non-cellular
components (serum) in the blood.

Immunization/Vaccination
Purposeful exposure of individual to
infectious material to elicit immunity.
 Early forms of vaccination were
developed in ancient China as early as
200 B.C.
 People inhaled powdered scabs from
people infected with smallpox to protect
against the disease.

Vaccination – Edward Jenner
Smallpox affected all levels of society.
 Jenner noticed that milkmaids did not
generally get smallpox.
 Jenner theorized that the pus in the
blisters which milkmaids received from
cowpox (a disease similar to smallpox, but
much less virulent) protected the
milkmaids from smallpox.

Vaccination – Edward Jenner
Inoculated 8 yr old with material from
pus in cowpox blisters.
 Exposed boy to infectious agents and no
disease followed.
 Jenner's unique contribution was not that
he inoculated a few persons with cowpox,
but that he then proved they were
immune to smallpox.
 Process called vaccination, from vacca,
Latin for cow.

Ethical Smallpox Issue
“Last Samples Of Smallpox
Pose a Quandary”
This article was written before 9/11 but it
is still a thought provoking article.
http://tinyurl.com/26khtnt
 What are your thoughts? Post them to
the Discussion Board in BlackBoard.

Vaccination


A vaccine - biological preparation that elicits
immunity to a particular disease.
A vaccine may be:
◦ Weakened forms of pathogens
◦ Killed or inactivated forms of pathogens
◦ Purified material such as proteins which are similar to
pathogens.

Stimulates the body's immune system to recognize
the agent (antigen) as foreign, destroy it, and
"remember" it, so that the immune system can
more easily recognize and destroy any of these
microorganisms that it later encounters.
Vaccination - Types





Killed microorganisms
Attenuated – live organisms cultivated to
disable virulent properties
Toxoid - inactivated toxic compounds in cases
where these (rather than the micro-organism
itself) cause illness
Subunit -fragments create an immune response
Conjugate-linking outer coats to proteins which
can the lead immune system to recognize
Rabies
Rabies
A viral disease that causes acute encephalitis
(inflammation of the brain).
 It is zoometric (i.e., transmitted by animals),
most commonly by a bite from an infected
animal but occasionally by other forms of
contact.
 The period between infection and the first
flu-like symptoms is normally two to twelve
weeks, but can be as long as two years.
 Rabies is almost invariably fatal if postexposure prophylaxis is not administered
prior to the onset of severe symptoms.

Rabies
Louis Pasteur applied the principle of
attenuation to a rabies vaccine.
 Developed a rabies virus that was milder and
had a shorter incubation (development) period
than the wild virus.
 A person bitten by a rabid animal would be
inoculated with the Pasteur virus and rapidly
develop immunity to the wild strain.

Rabies
He developed his rabies vaccine by growing the
virus in rabbits, then drying the affected nerve
tissue (spinal cords) to weaken the virus.
 On July 6, 1885, the vaccine was administered to
a 9-year-old boy who had been attacked by a
rabid dog.
 The boy survived and avoided contracting
rabies, which would have almost certainly
proved fatal.


http://www.historylearningsite.co.uk/louis_pasteur.htm
End of Unit 1 Part 1