Immunisation Flashcards
(11 cards)
Why are vaccines give to people?
To confer immunity against infectious diseases
The body will also create memory cells which then confers immunity should the person be exposed to the real virus in the future
The immune system will respond but person won’t experience symptoms
What are the four forms of a vaccine?
Inactivated pathogen toxins
Dead pathogens
Part of pathogens
Weakened pathogens
What are antigens usually mixed with when producing a vaccine?
A chemical called an adjuvant
What’s an adjuvant?
A substance which makes the vaccine more effective, so enhancing the immune response
When does herd immunity occur?
Why’s it important to establish?
When a large percentage of the population is immunised
Establishing herd immunity is important in reducing the spread of diseases
What is herd immunity?
It explains the fact that non-immune individuals are protected as there is a low probability they will come into contact with infected individuals
What is the herd immunity threshold?
What does it depend on?
The percentage of the population that must be vaccinated in order for herd immunity to be achieved
It depends on the type of disease, the effectiveness of the vaccine and the density of the population
What are mass vaccination programmes designed to do?
Establish herd immunity to a disease
When will herd immunity not be achieved/difficult to achieve?
When widespread vaccination is not possible due to
Poverty in the developing world
When vaccines are rejected by a percentage of the population in the developed world(more chance of infection spreading)
What is antigenic variation?
Some pathogens can change their antigens meaning that memory cells aren’t effective against them
Explain antigenic variation in terms of influenza
It shows high antigenic variation meaning the public are exposed to many different forms of the virus
This explains why the flu poses a major health risk and individuals at risk must be vaccinated each year to protect them from the changing virus
