Unit 3: Neurobiology and Immunology - Key Area 7/8: Immunisation/Clinical Trials of Vaccines and Drugs Flashcards
How can immunity be developed?
By vaccination with antigens from infectious pathogen, so creating memory cells.
What are the antigens used in vaccines?
Inactivated pathogen toxins, dead pathogens, parts of pathogens and weakened pathogens.
What are antigens mixed with when producing the vaccine?
An adjuvant
What are adjuvants?
Substances which make the vaccine more effective and so enhances the immune response.
What is an example of a disease where immunity is acquired from an inactivated pathogen?
Diphtheria and tetanus.
What is an example of a disease where immunity is acquired from a weakened pathogen?
MMR - measles, mumps and rubella.
What is an example of a disease where immunity is acquired from a dead pathogen?
Poliomyelitis and hepatitis A
What is an example of a disease where immunity is acquired from an parts of pathogen?
HPV against cervical cancer and hepatitis A.
What is the difference between vaccination and immunisation?
Immunisation is what happens in your body after you have had a vaccination.
The vaccination which contains inactivated or weakened pathogens stimulate your immune system so that it can recognise and protect you from future infection.
When does herd immunity occur?
When a critical/large percentage of a population are immunised.
What is establishing herd immunity important for?
Establishing herd immunity is important in reducing the spread of diseases and in protecting vulnerable and non-immune individuals.
How does herd immunity protect non-immune individuals?
If a large percentage of the population are immunised, non-immune individuals are protected as there is a lower probability that they will come into contact with infected individuals.
What does the herd immunity threshold depend on?
The type of disease, the efficacy of the vaccine and the density of the population.
When can difficulties occur with widespread vaccination?
It is not possible due to poverty in the developing world, or when vaccines are rejected by a percentage of the population in the developed world.
What have some pathogens done to evade the immune system?
They have evolved mechanisms (changed their antigens)
What does the fact some pathogens change their antigens mean for memory cells and what is this called?
They are not effective against them and this is called an antigenic mutation.
What happens to the influenza virus which means that it is a major public health problem and how do we combat this?
Antigenic variation occurs. Individuals who are at risk need to be vaccinated every year because of it.
Why are vaccines and drugs subject to clinical trials?
Vaccines and drugs are subjected to clinical trials to establish their safety and effectiveness before being licensed for use.
What is the description for randomisation?
Randomly separated:
- test group/control group.
- similar composition e.g. gender, age, health, etc.
- eliminates bias (via computer selection/pick out of hat).
What is the description for a placebo - control?
- Non effective treatment - lacks active ingredient.
- Placebo effect - thoughts/feelings.
- example could be a sugar pill.
What is the description of a double blind trial?
Neither subjects or doctors know who is receiving what.
What is the importance of group size in clinical trials?
Reduce experimental error and establish statistical significance.
