This lesson will increase your knowledge of concepts covered in the following TEKS for biology:

1
This lesson will increase your knowledge of
concepts covered in the following TEKS for
biology
3.a Analyze, review, and critique scientific
explanations, including hypotheses and theories,
as to their strengths and weaknesses using
scientific evidence and information 3.c
Evaluate impact of research on scientific
thought, society, and the environment  3.f
Research and describe the history of biology and
contribution of scientists. 4.c Compare the
structures and functions of viruses to cells and
describe the role of viruses in causing diseases
and conditions such as acquired immune deficiency
syndrome, common colds, smallpox, influenza, and
warts 4.d Identify and describe the role of
bacteria in causing disease
2
10.a Interpret the functions of systems in
organisms 10.b Compare the interrelationships
of organ systems to each other and to the body as
a whole 11.d Summarize the role of
microorganisms in maintaining and disrupting
equilibrium including diseases in plants and
animals and decay in an ecosystem
3
Previous Lesson Immune System, Viruses and
Bacteria
4
Question How does your immune system identify
the specific microbe attacking your body?
5
Microbe with protein coat enters body and starts
to reproduce
Immune System Response
Macrophages circulate thru body and ingest some
of the microbes, alerting Helper T cells by
presenting protein coat
Helper T cells recognize protein coat of microbe
and alert T and B cells with cytokines
B cells make antibodies that neutralize microbes
Killer T cells kill microbe or human cells
infected with microbes
Memory B cells remain to provide immunity
Memory T cells remain to provide immunity
6
Question Why does a cold virus attack you and
why does it take you 7-10 days to get over the
common cold?
Based on Mader, S., Inquiry into Life,
McGraw-Hill
7
A virus attacks you because

• Viruses do not have
• ribosomes and
• cannot make their
• own protein
• They need the
• ribosomes of your
• cells to make their
• proteins
• You are their host

Based on Harvard Medical School Family Health
Guide
8
Microbe with protein coat enters body and starts
to reproduce
The immune system takes about 7-10 days to make B
cells and Killer T cells to wipe out the viruses
Macrophages circulate thru body and ingest some
of the microbes, alerting Helper T cells by
presenting protein coat
Helper T cells recognize coat of microbe and
alert T and B cells with cytokines
B cells make antibodies that neutralize microbes
Killer T cells kill microbe or human cells
infected with microbes
Memory B cells remain to provide immunity
Memory T cells remain to provide immunity
9
Question How does a person get shingles?
10
Shingles is a disease in which the chickenpox
virus, hiding in the nervous system, becomes
active and causes blisters on the surface of the
body
Based on Harvard Medical School Family Health
Guide
11
Question McCall Akin died from E. coli
poisoning. How does E. coli cause death?
From Time, August 3, 1998
12
Based on Time, August 3, 1998

• One strain of E. coli has extra genes that allow
  it to stick to the walls of the intestine and
  produce a potent toxin
• The toxin injures the cells of the intestinal
  wall, leading to bleeding
• The toxin travels in the bloodstream to the
  kidneys, leading to renal failure

13
Todays Lesson Vaccines and Disease Prevention
14
Overview of Lesson

• History of the smallpox vaccine
• Vaccines and the immune system
• Polio

15
History of Smallpox
From Newsweek, October 14, 2002
16
Development of Smallpox Vaccine
In late 1790s, Dr. Edward Jenner observed that
dairy maids did not get smallpox He postulated
that their exposure to cowpox protected them from
smallpox He tested his hypothesis by scratching
the pus from cowpox lesions into the skin of a
non-infected person Exposure to cowpox resulted
in protection from smallpox (the viruses have
very similar protein coats)
17
Jenner published his findings in 1798 Smallpox
vaccine was one of the first vaccines
From Scientific American, November 1976
18
Scientists now know that smallpox is caused by a
virus transmitted in contaminated droplets or in
contaminated clothes
Smallpox Viruses
Based on Newsweek, October 14, 2002
19
Smallpox in the Body
Days 1-5 Viruses in contaminated air droplets
or clothes are inhaled Viruses spread from the
lungs to the lymph nodes
Based on Newsweek, October 14, 2002
20
Days 6-17 Viruses migrate to liver and spleen,
where multiply rapidly
Based on Newsweek, October 14, 2002
21
Days 18-20 Flu- like symptoms and sores begin
in mouth and throat People are highly contagious
during this stage
Based on Newsweek, October 14, 2002
22
Days 21-37 Pustules appear on the limbs and
torso The disease is most deadly during this
stage, causing death in 40 of cases
Eventually, pustules scab over
Based on Newsweek, October 14, 2002
23
Smallpox Days after infection
Day 24
Day 26
Day 31
Day 28
Day 46
Day 36
From Scientific American, November 1976
24
Smallpox vaccine Injection of live cowpox
viruses that cause antibodies and memory cells
for cowpox and smallpox
Based on Newsweek, October 14, 2002
25
The World Health Organization (WHO) began a
vaccination campaign against smallpox in the
1960s
Decline in Number of Countries Reporting Smallpox
Cases
Based on Scientific American, October 1976
26
Areas afflicted with smallpox declined during the
60s and 70s Smallpox was eradicated in the
wild by 1977
Based on Scientific American, October 1976
27
Stopped Immunizations

• Risk of reaction to the vaccine is greater than
  risk of getting smallpox
• There are now millions of people not protected
  against smallpox

28
From Science, November 19. 1993
The Controversy Over Smallpox
From Science, November 19, 1993
29
Overview of Lesson

• History of the smallpox vaccine
• Vaccines and the immune system
• Polio

30
The Vaccine Concept
Expose a human to a foreign protein associated
with a disease-causing microbe (dead microbe,
live but weakened microbe, altered toxin) The
immune system responds and eventually makes
antibodies and memory cells for that specific
protein and disease
31
Protein from microbe is injected into body
Immune System Response to Vaccination
Macrophages circulate thru body and ingest some
of the foreign protein, alerting Helper T cells
by presenting protein coat
Helper T cells recognize protein coat and alert
T and B cells by producing cytokines
Killer T cells develop to kill microbe or human
cells infected with microbes with that protein
coat
B cells make antibodies that neutralize
microbes with that protein coat
Memory B cells remain to provide immunity
Memory T cells remain to provide immunity
32
Before the age of 12, kids receive up to 22
inoculations and booster shots
Hepatitis B Hepatitis B booster Hepatitis B
booster Hepatitis B assessment DTP (Diphtheria
Tetanus and Pertussis, or whooping cough) DTP
booster DTP booster DT HiB (Hemophilus
influenzae) HiB booster Polio Polio booster Polio
booster MMR (Measles, Mumps, Rubella) MMR
booster MMR assessment Varicella Varicella
assessment
Birth2 months 14 months 618 months 1112
years 2, 4, and 6 months 1518 months 46
years 1116 years 4 and 6 months 1215 months 2
and 4 months 618 months 46 years 1215
months 46 years 1112 years 1218 months 1112
years
Based on Starr, C., Biology Concepts and
Corrections, Brooks/Cole
33
Based on Starr, C., Biology Concepts and
Corrections, Brooks/Cole
34
The Vaccine Controversy
From Newsweek, July 31, 2000
From Time, September 13, 1999
35
Measles
Based on Science, February 26, 1982
36
Whooping Cough
Based on Science, February 26, 1982
37
Bottom Line on Childrens Vaccines
For unvaccinated children, the risk of getting
the disease is much greater than the risk of
complications from the vaccine
Based on Mader, S., Inquiry into Life,
McGraw-Hill
38
Overview of Lesson

• History of the smallpox vaccine
• Vaccines and the immune system
• Polio

39
Effects of Polio

• Polio is caused by a virus that attacks the
• nervous system and prevents nerve
• impulses being sent to the muscles
• Without nerve impulses, muscles weaken
• and a person becomes crippled or dies

X
Based on Mader, S., Inquiry Into Life,
McGraw-Hill
40
History of Polio in the U.S.

• 1916 - First major outbreak
• 1952 - Epidemic peaks with 57,879
• cases
• 1955 - Salk vaccine introduced
• 1961 - Sabin vaccine introduced
• 1979 - Last polio outbreak (10 cases)

41
Salk versus Sabin Vaccine
Salk Vaccine -made of killed polio
viruses -protects against polio but a person can
carry it Sabin Vaccine -made of live but
weakened polio viruses -protects against polio
and against carrying polio -in rare instances,
person can get polio
42
Each year, 5 - 8 cases of polio are caused by the
Sabin vaccine
From Time, October 30, 1995
43

• World Health
• Organization (WHO) working to eradicate polio
• WHO campaign began 1988
• Cases down then up
• 2000 deadline not met
• Global Polio Eradication Initiative

From U.S. News World Report, August 30, 1999
44
Challenges in Defeating Polio
Only 1/200 people infected with polio are
paralyzed The rest are carriers and capable of
spreading the virus in their feces It will be
difficult to eliminate all the carriers to the
point that we can stop the vaccination programs
for polio
45
Current Approaches

• In countries without polio cases, the Salk
  vaccine is used
• In countries with polio cases, the Sabin vaccine
  is used to prevent polio as well as carriers

46
Modern air travel means that polio is just one
plane ride away
Distribution of Polio
Based on Science, January 9, 1998
47
Next Lesson HIV Infection and AIDS