Immunisation Flashcards
What is immunisation
The process by which a person develops immunity to a disease-causing organism
What do vaccines include
Antigens from infectious pathogens that lead to the creation of memory cells.
What types of antigens can be used in vaccines
Inactivated pathogen toxins, weakened pathogens, dead pathogens, parts of pathogens
What are adjuvants
An adjuvant is a substance which makes a vaccine more effective
When does hers immunity occur
When a large percentage of a population is immunised against a disease
How does herd immunity protect non immune individuals
They have a lower probability of coming into contact with infected individuals
What is the herd immunity threshold
when The percentage of immune individuals in a population is above which a disease no longer manages to persist
What determines the herd immunity threshold
Type of disease, effectiveness of disease and density of the population
Mass vaccination programmes are..
designed to establish herd immunity against a disease
What difficulties can arise with here immunity
May not be possible due to poverty and may not occur due to vaccine rejection
What is antigenic variation
Some pathogens can change their antigens. This means that memory cells are not effective against them.
Give an example of antigenic variation
Antigenic variation occurs in the influenza virus explaining why it remains a major public health problem and why individuals who are at risk require to be vaccinated every year.
