Discovering vaccines

Lesson 5

How vaccines were discovered and developed

Learning outcomes & key terms

  • Students will be able to explain how vaccines were discovered
  • Students will understand the difference between a vaccination and variolation
  • Students will know the scientists who were involved in the discovery of vaccines
  • Students will understand how scientific method has progressed over time

 

Variolation: inoculation into skin of material from the pocks of variola (smallpox)

Vaccination: treatment with a vaccine to produce immunity against a disease

Understanding science

Biological science

Describing how the requirements for life (for example oxygen, nutrients and water) are provided through the coordinated function of body systems – such as the respiratory, circulatory, digestive and nervous systems

Explaining how body systems work together to maintain a functioning body using models, analogies and flow diagrams

Investigating the response of the body to changes as a result of the presence of germs

Science as a human endeavour

Scientific understanding, including models and theories, is contestable and is refined over time through a process of review by the scientific community

Advances in scientific understanding may rely on technological advances and are often linked to scientific discoveries

People use scientific knowledge to evaluate whether they accept claims, explanations or predictions. Advances in science affect people’s lives and generate new career opportunities

Values and needs of contemporary society can influence the focus of scientific research

Science enquiry skills

Formulate questions or hypotheses that can be investigated or tested

Analysing patterns in data can explain relationships between variables and also identify inconsistencies

Meet Prof Ian Frazer, a vaccine inventor

Prof Booy interviews Prof Frazer, the co-inventor of the HPV Vaccine, which is eliminating cervical cancer around the world – first in Australia!

About vaccination

Many diseases that were once killers are now eliminated (locally) or eradicated (globally) due to the impact of vaccines

Until recently, most people in developed countries have not had their daily routines impacted by an outbreak of disease and have taken vaccination for granted

Vaccines

Vaccines may contain a microorganism or virus in a weakened, live or killed state, or proteins or toxins from the outside of the germ. In stimulating the body’s adaptive immunity they help prevent sickness from an infectious disease

Vaccination

Vaccination is the administration of a vaccine to help the immune system develop protection from a disease

When a sufficiently large percentage of a population has been vaccinated, herd immunity results

The effectiveness of vaccination has been widely studied and verified

Vaccination is the most effective method of preventing infectious diseases. Widespread immunity due to vaccination is largely responsible for the worldwide eradication of smallpox and the elimination of diseases such as polio and tetanus from much of the world

Variolation

Variolation or inoculation was the method first used to immunise an individual against smallpox (Variola) with material taken from a patient in the hope that a mild, but protective, infection ensues

The procedure was most commonly carried out by inserting/rubbing powdered smallpox scabs or fluid from pustules into superficial scratches made in the skin

The patient would develop pustules identical to those caused by naturally occurring smallpox, usually producing a less severe disease than naturally acquired smallpox

Eventually, after about two to four weeks, these symptoms would subside, indicating successful recovery and immunity

(Wikipedia)

Case study

Smallpox eradicated from the world

Interest in smallpox started as long ago as 1000 AD when the Chinese started measures to prevent further spread of the disease

They would collect diseased cells from an infected person and then dry them out by carrying the cells in their pocket. They would then scratch a healthy persons arm and put in some dried cells

Skip forward to 1545 and there was an epidemic in India – 8000 children died

The process the Chinese used became known as variolation which became very popular in the early 1700s

In 1721, Lady Mary Montagu had variolation used for her 2 year old daughter, but not everyone agreed with the process of variolation

Variolation was sometimes fatal: two to three percent of those variolated died of smallpox (in contrast to 20-30% who died after contracting smallpox naturally)

Unfortunately those who were variolated could still have enough active disease to infect others (not the best way to defend against disease)

In 1770 real progress was made into the control of Smallpox

Edward Jenner (1749-1823), an English doctor, heard from a milkmaid that she believed herself protected from smallpox because she had caught cowpox from a cow

Cowpox is an uncommon illness in cattle, usually mild, that can be spread from a cow to humans via sores on the cow being milked

During an infection, dairy workers may have pustules on their hands – sufferers can spread the infection to other parts of the body

We know now that the cowpox virus belongs to the orthopox family of viruses. Orthopox viruses also include monkeypox virus and variola virus which causes smallpox

Whilst Jenner had ideas about how to vaccinate it wasn’t until 1796 that he tested his hypothesis on an 8 year old boy (James Phipps) with great success

This test lead to the vaccine that we have today

To further the story, in 1855 laws were passed to mandate vaccination

By 1980, Frank Fenner presented at the World Heath Assembly that smallpox was eradicated

Leaders of immunology

 

Edward Jenner

Edward Jenner is known as the ‘father of immunology’ and is famous for his smallpox vaccine

This was the first successful vaccine to ever be developed

Edward Jenner was born on May 17, 1749, in Berkely, Gloucestershire, England – he died of a stroke in 1823

Jenner wasn’t always met with adoring fans

In 1802, a caricature appeared of Jenner treating patients and those around him sprouting cattle- like appendages

Fears emerged about vaccination

During the eradication of smallpox, there always had to be a last patient- Ali Maow Maalin was exposed to the disease on October 12, 1977

Ali came into contact with the disease and developed a fever. When he was first diagnosed he was told he had chickenpox and sent home

When it was finally obvious that he had smallpox he kept it to himself and didn’t go into isolation. He came into contact with 91 people during his illness

The WHO (World Health Organisation) took precautions to stop any rekindling of the disease

They did a massive search and found all 91 people

No-one got ill and two years after watching the area carefully, smallpox was declared gone

 

Louis Pasteur

Louis Pasteur furthered the vaccine concept through his work in microbiology. His experiments spearheaded the development of live attenuated cholera vaccine and inactivated anthrax vaccine in humans (1897 and 1904, respectively)

 At the age of 46, he had a stroke but recovered sufficiently to do some of his best work

For example, in the 1870s, he applied his previous method of immunising chickens against chicken cholera to anthrax, which affected cattle and thereby aroused widespread interest in combating other diseases with the same approach

In May 1881, Pasteur performed a famous public experiment at Pouilly-le-Fort to demonstrate his concept of vaccination, in this case against anthrax

He prepared two groups of 25 sheep, one goat and several cow. The animals of one group were twice injected, with an interval of 15 days, with an anthrax vaccine prepared by Pasteur; a control group was left unvaccinated

Thirty days after the first injection, both groups were injected with a culture of live anthrax bacteria. All the animals in the non-vaccinated group died, while all in the vaccinated group survived

The public reception was jubilant

Class activity

Part 1

  • You will work in groups of 3
  • You will create a slide on one of the topics below (decided by your teacher)
  • Each member of the group try a different summarising method (using the methods that follow) and present the information on one slide
  • Find pictures that represent your findings for another slide (method 2)
  • The finished slides (2 in total – one info and one graphic) should then be printed off and arranged in order for the class to see

 

Choose a method to create your slides

Method 1

  • Delete unwanted extra (trivial) details that can go without losing the overall sense
  • Delete information that is repeated in some way
  • Replace the details with more general terms or descriptions
  • Select a topic sentence or create 1 if it is missing
  • Check there is sufficient detail to make sense

 

Method 2

  • Create a visual representation of key aspects of the information such as a table, chart, flow diagram or spider diagram
  • Try to show the relationships between pieces of information where you can

Method 3 

  • Skimming – preview the information on the factsheet by highlighting the important information
  • Then focus on the headings and subheadings to write a short written summary of the factsheet

Topics

1. Variolation – 900-1000

  • What is variolation?
  • Who discovered and used it in this time period?
  • Was it effective?
  • What where the dangers with this method?

2. Lady Montagu – 1700’s

  • How did Lady Montagu contribute to the adoption of variolation?
  • How was this method different to previous variolation methods?
  • Was it effective?

3. Edward Jenner – 1796

  • Explain how Edward Jenner discovered the smallpox vaccination
  • When was smallpox officially eradicated from the world?
  • Was it effective?
  • What where the dangers with this method?

4. Variolation & vaccination – 1840

  • England banned variolation and only vaccination was allowed and provided free for the poor
  • What is the difference between variolation and vaccination?
  • Why do you think variolation was prohibited in favour of vaccination?

5. Louis Pasteur – 1880 & 1881

  • Pasteur developed and publicly demonstrated his anthrax vaccine
  • How did he convince his peers that his vaccine worked?

World Health Organisation – How Are Vaccines Developed?

Coming soon

Coming soon

Summary

In this lesson you have learned what vaccines are, the value to society and how they are discovered

Vaccines contain a microorganism in a weakened live or killed state, or the proteins or toxins from the outside of the germ. These stimulate the body’s adaptive immunity to help prevent disease

Vaccination is the administration of a vaccine to help the immune system develop protection

Vaccines are still being invented today by leaders such as Prof Ian Frazer – these modern day leaders build their vaccines on the science first developed by leaders such as Jenner and Pasteur

Quiz

1) Rubbing powdered smallpox scabs into superficial scratches on a well person’s skin is called
a) Vaccination
b) Immunity
c) Boosting
d) Variolation

2) The person credited with inventing the smallpox vaccine is
a) Edward Jenner
b) Louis Pasteur
c) Ian Frazer
d) Walter Orenstein

 

3) Smallpox was officially declared eradicated in
a) 1770
b) 1980
c) 1977
d) 1721

 

4) The cholera and anthrax vaccines were developed in the late 19th century by
a) Edward Jenner
b) Louis Pasteur
c) Ian Frazer
d) Walter Orenstein