Vaccines Flashcards
Why are vaccines so good?
- they are cheap
- they prevent illness
What does our immune system have that is beneficial, especially with vaccines?
A memory!
when we get exposed to an illness, the memory stored in our immune system allows us to not get as sick
What do illnesses + viruses do to our bodies?
they cause scarring in the respiratory system (wear + tear)
What is a vaccine?
it is a FAKE illness
- it manipulates the immune system and helps memory formation of an illness without getting it
What is a limitation of the immune system?
it is selective but very slow, there is a lag time and a ramp-up period (2-3 days) where an illness brews
we want to avoid this, so copies are made: ANTIBODIES
What are antibodies?
recognition devices: Y-shaped + sticky ends
- 3D shape
what is another name for antibodies?
immunoglobulin
2 kinds: IgD, IgM
What is the part of a virus that an antibody notice’s called?
epitope
What cells are antibodies found in?
B-cells
B-cells:
They carry antibodies, each cell carries a different one
- a small amount of them are stored but an immune response will trigger the replication of the one that is needed - and these target the invaders
- These become memory cells after infection
what percentage of B cells are in a new born vs someone who has gotten sick as they get older?
<5% vs. >50%
Where do viruses live in our body?
inside our cells - hard to access with antibodies
What system does the body use to get rid of viruses?
they use T-cells which carry receptors (carry information)
if T-cells make a sandwich with the MHC receptor the protein will be in between and the T cell will recognize + get rid of the infected cell
2 types of T-cells - what happens when they communicate?
Killer T-cells
Helper T-cells (cross check)
they look for infected cells
they communicate together, and the killer T cell will send a signal to the infected signal which tells it to die, apoptosis
What receptor is found on the outside of every cell? what does it do?
MHC
- collects fragments of proteins that are cut up and are displayed in the MCH receptors, if the protein comes from a human protein - good/ if the protein is a virus protein the MHC receptor will help trigger the process of cleaning out the cell
with this process of killing viruses, how do vaccines help?
they trick the immune system into thinking there’s a virus, memory cells will be formed in the process and will prevent future illness later on
what was a practice to protect against small pox in many cultures?
Variolation: you collect some of the puss from someone who has it and injects it into small children, so those that recover would be protected later on
Small Pox
20-40% mortality rate
if you survived you had a high probability of being disfigured 70-80%- scars
What is Edward Jenner do?
he noticed that some people didn’t get smallpox, people who worked closely with cows didn’t get it (milkmaid), and they contracted a disease from cows (cowpox) - maybe getting infected with it protected against smallpox
experiment:
- infected children with cowpox and then smallpox and they didn’t get it
- this was unique to smallpox only
VACCINATION!! - much better, people didn’t die with a “fake” virus
when was smallpox eradicated from developing countries? global program? last case?
1950’s, 1966, 1977
