Vaccines

Question 1

What is a vaccine?

Answer 1

A dead or weakened pathogen which stimulates the production of memory cells.

Question 2

What is herd immunity?

Answer 2

If enough people have a vaccine the disease will not spread through a population.

Question 3

What is antigenic variablity?

Answer 3

-Some pathogens change their surface antigens due to mutations.
-Memory cells don’t recognise different antigens so need new primary response.
-So new vaccines made.

Question 4

Why are vaccines not fully effective?

Answer 4

-Fails in certain individuals.
-Pathogens can mutate.
-Can hurt animals when testing.

Question 5

What are the diffences between passive and active immunity?

Answer 5

Passive:
-Antigen exposure not needed.
-Antibodies not produced.
-Immediate but short-term.
Active:
-Antigen exposure is needed.
-Antibodies are produced.
-Is a slow process but long lasting (forms memory cells).