Cells: Immunity and vaccine Flashcards
What is active immunity
A type of immunity you get hen your immune system makes its own antibodies after being stimulated by an antigen
Outline the two types of active immunity
- Natural - When you become immune after catching a disease
- Artificial - When you become immune after you’ve been given a vaccination containing a harmless dose of an antigen
What is passive immunity
A type of immunity you get from being given antibodies made by a different organism (your immune system doesn’t produce any antibodies n it own)
Outline the two types of passive immunity
- Natural - when a baby becomes immune due to the antibodies it receives from its mother, through the placenta and in the breast milk
- Artificial - When you become immune after being injected with antibodies from someone else
(e.g if you contract tetanus you can be injected with antibodies against the tetanus toxin, collected from blood donations)
State four differences of active and passive immunity
- Active immunity requires exposure to the antigen WHEREAS passive immunity does NOT
- With active immunity it takes a while for protection to develop WHEREAS with passive immunity protection is immediate
- With active immunity memory cells are produced, WHEREAS with passive immunity memory cells aren’t produced
*With active immunity protection is long-term because the antibody is produced in response to complementary antigen being present in the body WHEREAS with passive immunity protection is short term because the antibodies given are broken down
What are vaccines
A suspension of antigens that are intentionally put into the body to induce artificial active immunity
How do vaccines protect individuals
The vaccine can trigger an immune response without making an individual sick by using dead or attenuated pathogens
What kinds of antigens are present in vaccines
- Free antigens
- Antigens attached to a dead pathogen
- Antigens attached to an attenuated (weakened pathogen)
List ways vaccines can be taken
Injected or taken orally
State a disadvantage of taking vaccines orally (and how can this be solved)
- The vaccine could be broken down by enzymes in the gut
OR
- Molecules of the vaccines may be to large to be absorbed into the blood
- This can be solved by giving follow up booster vaccines later
What are booster vaccines
They are a type of vaccines offered to help maintain strong protection from a pathogen as some levels of protection may decline over time
Name a benefit on herd immunity
It protects immunocompromised people and other people who cannot take vaccines for medical reasons
When does herd immunity occur
When a significant portion of a population becomes immune to an infectious disease and the risk of spread from person to person decreases
Outline the ethical issues surrounding the use of vaccines
- All vaccines are tested on animals before humans
- Testing vaccines of humans can be risky and volunteers may put themselves as unnecessary risk of contracting the disease bc they think they are immune
- Some ppl don’t want to take the vaccine due to high risk, but they are still protected by herd immunity - other ppl think that this is unfair
- If there was an epidemic of a new disease, there would be difficult decisions on who would be the first to receive it
What is antigenic variation
Pathogens that can change their surface antigens
