B2-2 What are vaccines and antibiotics and how do they work? Flashcards
What is a vaccine?
A vaccine is a dead or inactive version of a micro-organism.
What does a vaccination do?
Vaccinations are something that provide immunity to certain illnesses - a head start in fighting the microbes that attack your body.
How is this possible?
First a dead or weak version of the microbe is injected into the body (harmless). These MO’s have the same antigens meaning the WBC will produce antigens. This means that memory cells will be left behind. When the actual disease comes into the body, it will be fought off as there are memory cells in place.
What does the MMR vaccine immunise?
Measles, mumps and rubella
How can epidemics be prevented?
If the majority of people are vaccinated, then the spread of diseases is very unlikely as even people that haven’t been vaccinated won’t get ill as there will be fewer people with the disease.
What is one disease that has been virtually wiped out?
Smallpox
What is an issue with vaccines and drugs?
They can never be completely safe for everyone as different people could have different side effects from them.
What is another issue?
Genetic differences mean that people will react differently e.g. anaesthetics may last for different periods of time for different people.
What are Antimicrobials?
Chemicals that kill or inhibit bacteria fungi and viruses.
What is an Antibiotic?
It is an Antimicrobial that is effective versus bacteria but not viruses.
What is it known as when antibiotics begin to stop working against bacteria and fungi?
Antibiotic Resistance
How does this happen?
Micro-organisms sometimes have random MUTATIONS in their DNA, sometimes meaning they are less affected by the antimicrobial.
What happens to this micro-organism?
It stays alive for longer, hence it multiplies more and leads to its gene of ‘resistance’ being passed on. All the divisions will have resistance now.
How can this be a problem?
You can’t easily get rid of them, meaning that they keep on developing. This can, overtime, turn into a SUPERBUG, which becomes resistant to most known antimicrobials.
What is an example of ‘Superbug’?
MRSA
How can we reduce antibiotic resistance?
- Only take antibiotics when necessary.
2. ALWAYS finish your course, even when you think you feel better, ensure that all microbes are DEAD.
How are drugs tested? In order of production?
Human body cells, living mammals (rats or monkeys), then finally humans in CLINICAL Trials.
What happens if the drug causes animals serious illness?
The testing is usually terminated
How many types of human trials are there?
3
What are these called?
Blind, Double Blind and Open-label.
What is a clinical trial?
This is a trial where real humans are tested with the drug.
What is the process of a clinical trial?
Step 1:
First the drug is tested for safety on healthy volunteers - this is to make sure there are no harmful side effects on a normal body.
Step 2:
If those results are good, they move on to testing on people suffering from the illness - tested for safety and effectiveness.
Step 3:
Placebos are usually used to compare what the two groups felt - placebo and non-placebo
Step 4:
If the drug works, the people with the real drug will have improved more than the others.
If there are side-effects, the real drug group will report feeling these more than the others.
What is a blind trial?
Where the patient doesn’t know whether they’re taking a real drug or not - this is to eliminate any psychological factors.
What is a double-blind trial?
This is where the doctors or the patients do not know - this is to remove the doctors influence while monitoring the effects.
What is an open-label trial?
This is where everyone knows all the information - this is used when it is not possible to mask the treatments being tested.
What are the ethical issues to using placebos in human trials?
People think it is unethical to give suffering patients a placebo as it could take away from the potential treatment of their illness and also give false hope.
What is the importance of long-term drug trials?
It is important because in some cases it takes a while for the drug to have the effect it was designed to. Also you could find out about any side effects which may appear after only a long time.
