Immunity & vaccines Flashcards
There are two types of immunity. Immunity can either be a___________ or p___________
- Active
- Passive
What is meant by active immunity?
Immunity developed due to exposure to a pathogen or its antigen and the immune system makes its own antibodies and memory cells
Does active immunity lead to long term or short term immunity? Why?
Long term immunity
- Memory cells are produced so if the antigen enters the body again it can form plasma cells
What is an example of natural active immunity?
When an individual becomes immune after catching a disease and creates antibodies and memory cells
What is an example of artificial active immunity?
When an individual becomes immune after vaccination as antibodies and memory cells are created
What is meant by passive immunity?
Immunity aquired after recieving antibodies from another organism
Does passive immunity lead to long term or short term immunity? Why?
Short term immunity
- No exposure to pathogen or its antigens so no plasma cells or memory cells produced
- However does provide immediate immunity
What is an example of natural passive immunity?
When a baby become immune due to the antibodies it recieves from placenta / breast milk
What is an example of artificial passive immunity?
When an idividual become immune through an injection or transfusion of antibodies
What is a vaccination?
A dose of attenuated / dead pathogens which is introduced to the body usually via injection
Why must vaccines contain attenuated or dead pathogens?
To prevent symptoms of the disease
How does vaccination provide immunity?
- Once the vaccine is injected containg the antigens, the primary immune response is stimulated to produced antibodies and memory cells against that pathogen
- If exposed to that pathogen again, the memory cells will rapidly divide into plasma cells and secrete antibodies and the pathogen is destroyed before any symptoms are produced
Why may booster vaccinations be given?
To ensure that an individual has a sufficient amount of memory cells
What is meant by herd immunity?
Where enough people in a population are immune which protects others in that population who arent immune as the pathogen cannot spread easily
Why might some people in a population not be able to get vaccinated?
- An individual may be too young
- An individuals immune system may be compromised
Why might some vaccines need to be updated?
Pathogens’ DNA can mutate frequently and if the mutation occurs in the gene that codes for the shape of the antigen, it will change shape
The antibodies will not recognise the shape of the new antigen and won’t provide an immune response
What are 4 ethical issues in the production and use of vaccines?
- Animal testing
- Human testing
- Epidemics
- Herd immunity
How is animal testing an ethical issue of vaccines?
- Vaccines are first tested on animals
- People disagree with animal testing
- Animal based substances may be used to produce a vaccine
How is human testing an ethical issue of vaccines?
- Can be risky and cause harm
- Risk of actually contracting the disease
- Vaccines may not work
How are epidemics an ethical issue of vaccines?
Rush to recieve the vaccine and decisions have to be made on who gets it first
How is herd immunity an ethical issue of vaccines?
- Some people do not want to take a vaccine but are still protected by herd immunity
- Others think this is unfair
Compare and contrast active and passive immunity
- Active involves memory cells, whereas passive does not
- Active involves the production of antibodies by plasma cells, whereas passive involves antibodies being introduced into the body from an external source
- Active provides long term immunity as antibody is produced in response to antigen and creates memory cells, whereas passive provides short term immunity as antibody is broken down and no memory cells are produced
- Active takes time to develop, whereas passive is fast acting
