immunisation

Question 1

how can immunity be developed

Answer 1

Immunity can be developed by vaccination using antigens from infectious pathogens, so creating memory cells.

Question 2

what does a vaccine contain

Answer 2

inactivated pathogen toxins, dead pathogens,

parts of pathogens and weakened pathogens.

Question 3

State the purpose of an adjuvant

Answer 3

An adjuvant is a substance which makes the vaccine more effective, so enhancing the immune response.

Question 4

State what herd immunity is

Answer 4

Herd immunity occurs when a large percentage of a population is immunised.

Question 5

why is herd immunity important

Answer 5

reduces spread of disease

Question 6

Explain how non immune individuals are protected

Answer 6

there is a lower probability they will come into contact with infected individuals.

Question 7

State what the herd immunity threshold depends on

Answer 7

type of disease, the effectiveness of the

vaccine and the density of the population

Question 8

explain the purpose of mass vaccination programmes

Answer 8

Mass vaccination programmes are designed to establish herd immunity to a disease.

Question 9

explain the difficulties that can arise from mass vaccination problems

Answer 9

Difficulties can arise when widespread vaccination is not possible due to poverty in the developing world, or when vaccines are rejected by a percentage of the population in the developed world.

Question 10

Explain what antigenic variation is and give an example

Answer 10

Some pathogens can change their antigens. This means that memory cells are not effective against them.
Antigenic variation occurs in the influenza virus explaining why it remains a major public health problem