4.4. Active Immunisation and Vaccination, and the Evasion of Specific Immune Responses by Pathogens Flashcards
What are vaccines?
Substances that contain a form of antigen that trigger an immune response but with no illness. This creates memory cells which protect against the antigen in the future.
Where can antigens for vaccinations be found?
From dead pathogens, weakened pathogens, parts of pathogens or inactivated toxins from pathogens.
What are adjuvants?
Substances that can be added to antigens and mixed to enhance an immune response. This may include releasing more antibodies.
What must be conducted to ensure the safeness of a vaccine?
Clinical trials on volunteers. These volunteers are split into a control and test group unbeknownst to them. The test group gets the vaccine while the control gets a placebo.
What does double-blind mean?
When neither the doctor nor patient know who has the vaccine and who has the placebo.
What is herd immunity?
When enough people are immune to disease in a population that they protect those who are not immune.
How can the herd immunity threshold be changed?
Based on:
The type of disease and how easily it spreads, the effectiveness of the vaccine itself and how mixed the population is.
What is public health immunisation?
Programmes in countries that schedule immunisations to aim towards herd immunity. In the UK, the NHS schedule immunisations for children ages 2 months to 14.
What are the two main problems in achieving herd immunity?
- Poverty and malnourishment mean that vaccines can be dangerous to people. This means herd immunity is impossible.
- Vaccinations are voluntary in developed countries. Parents may refuse their child from being immunised which will decrease the possibility of achieving herd immunity.
