Topic 2---C: Cells and The Immune System- 3. Immunity and Vaccines Flashcards
What is active immunity?
This is the type of immunity you get when your immune system makes it’s own antibodies after being stimulated by the antigen.
What is natural active immunity?
This is when you become immune after catching a disease.
What is artificial active immunity?
This is when you become immune after you’ve been given a vaccination exposing you to a harmless dose of antigen. (weakened version of a pathogen).
What is passive immunity?
This is the type of immunity you get from being given antibodies made by a different organism.
What is natural passive immunity?
This is when a baby becomes immune due to the antibodies it receives from it’s mother, through the placenta to her foetus in breast milk.
What is artificial passive immunity?
This is when you become immune after being injected with antibodies from someone else.
What are the differences between active and passive immunity?
- Active immunity requires exposure to antigen but passive immunity doesn’t.
- Active immunity takes a while for protection to develop but passive immunity protection is immediate.
- Active immunity there are memory cells produced but memory cells aren’t produced in passive immunity.
- In active immunity protection is long term because the antibody is produced after activation of memory cells in response to complementary antigen being present in the body. but in passive immunity protection is short term as the antibodies given are broken down.
What is a vaccine?
It’s a dead or weakened form of a pathogen that stimulates an immune response.
Why are vaccines given?
- They stimulate the primary immune response.
- They protect individuals and reduce the occurance of the disease.
- Antigens in vaccines cause your body to produce memory cells against a particular pathogen without the pathogen causing a disease.
- This means you become immune without getting any symptoms.
What is herd immunity?
It’s when unvaccinated people are protected because the occurance of the disease is reduced by the number of people who are vaccinated as there are fewer people to catch it from.
What do vaccines usually contain?
Antigens that may be free or attatched to a dead or weakened pathogen.
How can vaccines be took?
They may be injected or taken orally.
What is a disadvantage of taking a vaccine orally?
- It can be broken down by enzymes in the gut before being absorbed by the body or the molecules of the vaccine may be too large to be absorbed into the blood.
Why are booster vaccines given later on?
- To make sure that more memory cells are produced.
- To ensure memory cell production.
What are the ethical issues surrounding the use of vaccines?
- All vaccines are tested on animals before being tested on humans- some people disagree with animal testing.
- Also animal based substances may be used to produce a vaccine which some people disagree with.
- Testing vaccines on humans can be risky e.g. volunteers might put themselves at unnecessary risk of contracting the disease because they think they’re fully protected.
- Some people don’t want to take the vaccine due to the risk of side effects but they are still protected from herd immunity- other people think this is unfair.
- if there was a new epidemic of a new disease there would be a rush to receive a vaccine and difficult decisions would have to be made about who would be the first to receive it.
