Neurobiology and Immunology: Immunisation Flashcards
How can immunity be developed?
By vaccinations using antigens from infectious pathogens, so creating memory cells
What can the antigens used in vaccines be?
Inactivated pathogen toxins, dead pathogens, parts of pathogens and weakened pathogens
What are antigens usually mixed with when producing the vaccine?
An adjuvant
What is an adjuvant?
A substance which makes the vaccine more effective, so enhancing the immune response
When does herd immunity occur?
When a large percentage of a population is immunised
Why is establishing herd immunity important?
To reduce the spread of disease
How are non-immune individuals protected?
There is a lower probability they will come into contact with infected individuals
What does the herd immunity threshold depend on?
The type of disease, the effectiveness of the vaccine and the density of the population
What are mass vaccination programmes designed for?
To establish herd immunity to a disease
When are there difficulties with widespread vaccination?
Poverty in the developing world, malnutrition or when vaccines are rejected by a percentage of the population in the developed world.
What can some pathogens change and what does this mean?
Antigens.
Memory cells are not as effective towards them
What occurs in the influenza virus?
Antigenic variation occurs explaining why the flu remains a major public health problem and why individuals who are at risk require to be vaccinated every year.
