1. IMMUNITY
© 2016 Paul Billiet ODWS

2. Active immunity Passive immunity
Infection of pathogen or injection of vaccine
Antibodies acquired from a host
Mother ,via placenta or milk (colostrum)
Immunised organism (e.g. horse) or monoclonal antibodies
Immune response
Antibodies produced and memory cells retained
Infection destroyed
No memory cells created because the body has not produced an immune response itself
Infection destroyed
Infection by the same pathogen
New, rapid immune response
Further infections possible by the same pathogen.

3. VACCINES AND VACCINATION
Vaccination is a prophylactic treatment
Some are used as post infection vaccination
It stimulates the immune system by exposing it to harmless antigens
The immune response leaves memory cells
Response to a real infection is rapid and the body resists.
© 2016 Paul Billiet ODWS

4. A typical immune response to vaccination
Primary immune response, slow to build up and not very strong.
Antibody response
Time
Secondary response stronger and more rapid than primary response
Memory cells remain
Infection by pathogen
Vaccination
© 2016 Paul Billiet ODWS

5. Vaccines
Vaccines: Purified antigens from the pathogen Dead pathogens or parts of pathogens Live but attenuated (harmless) pathogens
Memory is not perfect, booster vaccination may be necessary
Vaccines are usually limited to those diseases that are endemic to the region because of complications.
© 2016 Paul Billiet ODWS

6. The benefits and dangers of vaccination
Vaccination has helped to cut infantile death rates in many parts of the world
Some diseases (e.g. small pox) have been eliminated totally
Others (e.g. polio) are programmed for elimination
Vaccination has helped to contain the spread of a number of diseases
Vaccines are a cheap form of prophylactic treatment.
© 2016 Paul Billiet ODWS

7. The benefits and dangers of vaccination
Live vaccines containing attenuated viruses may “jump” to another virus in the system e.g. attenuate live polio virus given to a person contaminated with HIV may develop polio
Vaccines may lead to allergic responses or auto immune diseases e.g. Crohn’s disease
Multiple vaccinations received by soldiers fighting in the Gulf War 1991 are associated with a number of health problems (The Gulf War Syndrome).
© 2016 Paul Billiet ODWS

8. Vaccines: a victim of their own success
Infectious diseases become rarer in a population
The attention of parents tends to be focussed on the problems with vaccines
They become reluctant to vaccinate their children or …
they become complacent about the risk of infection
1990 in the United States, an outbreak of cases of measles, 30 children died.
© 2016 Paul Billiet ODWS

9. The small pox story Variolation Edward Jenner (1796) & cow pox
Vaccination
Eradication programme
Polio next?
© 2016 Paul Billiet ODWS

10. Small pox WHO global eradication plan 1966
© 2016 Paul Billiet ODWS

11. Polio WHO global eradication plan 1988
© 2016 Paul Billiet ODWS