Vaccination

Question 1

How can immunity be developed?

Answer 1

By vaccination using antigens from infectious pathogens, so creating memory cells

Question 2

In what form can the antigens used in vaccines be?

Answer 2

Inactivated pathogen toxins, dead pathogens, parts of pathogens and weakened pathogens

Question 3

What are antigens mixed with in a vaccine and what is the effect of this substance?

Answer 3

Adjuvant - this makes the vaccine more effective, enhancing the immune response

Question 4

When does herd immunity occur?

Answer 4

When a large percentage of a population are immunised

Question 5

Why is establishing herd immunity important?

Answer 5

To reduce the spread of diseases.

Question 6

Why are non-immune individuals protected by herd immunity?

Answer 6

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

Question 7

What does the herd immunity threshold depend on?

Answer 7

Type of disease, density of population and effectiveness of vaccine

Question 8

When can difficulties arise in herd immunity?

Answer 8

When widespread vaccination is not possible due to poverty, or when vaccines are rejected by a percentage of the population (‘‘anti-vaxxers’’)

Question 9

When pathogens change their antigens, what is this called?

Answer 9

Antigenic variation

Question 10

When antigenic variation occurs, what cells are no longer effective against the pathogen?

Answer 10

Memory cells

Question 11

Why is Influenza a major public health problem?

Answer 11

Antigenic variation occurs in this virus, and so individuals who are at risk require to be vaccinated every year