Immunisation

Question 1

State how immunity can be developed by vaccination

Answer 1

An individual can be immunized with a vaccine containing antigens from infectious pathogens, thus, creating memory cells in the individual

Question 2

State the types of antigens used
in a vaccine

Answer 2

weakened pathogens
Inactivated pathogen toxins
parts of pathogens
dead pathogens

Question 3

Name the substance antigens are
mixed with to make a vaccine

Answer 3

adjuvant

Question 4

State the purpose of an adjuvant

Answer 4

It makes the vaccine more effective in
enhancing the immune response

Question 5

What is meant by herd immunity?

Answer 5

when a large percentage of the population
is immunised against a particular pathogen

Question 6

Why is herd immunity considered
to be advantageous?

Answer 6

It reduces the spread of disease

Question 7

Why are non-immune individuals
protected by herd immunity?

Answer 7

Less likely to come into contact with
infected individuals

Question 8

State the three factors on which
herd immunity depends

Answer 8

Type of disease
effectiveness of vaccine
density of population

Question 9

Suggest why widespread
vaccination might not be achieved

Answer 9

Poverty or rejection of the vaccine by a
percentage of the population

Question 10

Suggest a reason why memory cells
are not always effective against some
pathogens

Answer 10

Some pathogens change their antigens
meaning that memory cells are no longer
effective against them

Question 11

Give an example of a virus that
displays antigenic variation

Answer 11

Influenza

Question 12

Explain the significance of antigenic variation in the administration of the influenza vaccine

Answer 12

At risk individuals require vaccines each
year against different strains of the virus