Key Area 4.4: Acitve Imminisation Amd Vaccination Flashcards
How can active immunity be developed?
By vaccination with antigens from infectious pathogens to create immunological memory
What can be mixed with antigens from infectious pathogens to enhance the immune response generated by a vaccine?
Adjuvants.
What are sources of antigens?
Inactivated pathogen toxins, dead pathogens, parts of pathogens and weakened pathogens.
What do vaccines undergo?
Clinical trials to establish their safety and effectiveness.
What are some designs of clinical trials?
Randomised, double blind and placebo controlled protocols.
What is important when carrying out a clinical trial?
Group size and replicates because they can affect the reliability of results and the significance of any statistics collected.
What is herd immunity?
When a large percentage of a population is immunised. Non immune individuals are protected as there is a lower probability they will come into contact with infected individuals.
What does the herd immunity threshold depend on?
The disease, the effectiveness of the vaccine and the contact parameters for the population.
What do public health immunisation programs aim to do?
Establish herd immunity to a number of diseases.
When is widespread vaccination not possible?
When populations are malnourished, in poverty, or a percentage of the population rejects the vaccine.
What have many pathogens evolved?
Mechanisms to evade specific immune responses.
What can some pathogens do to evade the immunological memory?
Change their antigens.
What are malaria and trypanosomiasis caused by?
Protozoa, which are carried by vectors and which are difficult to vaccinate against because they change their antigenic nature frequently.
What type of pathogens directly attack the immune system?
HIV and TB
What is HIV?
A virus that attracts lymphocytes and is the major cause of AIDS.
