vaccination and antigenic variation

Question 1

What do vaccines contain

Answer 1

Antigens which may be free or attached to a dead or attenuated pathogen

Question 2

What is antigenic variation

Answer 2

Pathogens change surface antigens due to changes in their genes. Memory cells produced from the first infection will not recognise the different antigens. Immune system carries out primary response again

Question 3

How does antigenic variation affect production of vaccines for influenza each year

Answer 3

Surface antigens change regularly forming new strains of the virus. Strains are immunologically distinct, memory cells will not recognise other strains w different antigens. New vaccines developed each year

Question 4

Active immunity

Answer 4

When the immune system makes its own antibodies after being stimulated by an antigen
Natural – after catching a disease
Artificial – harmless dose of antigen from vaccination

Question 5

Passive immunity

Answer 5

Given antibodies made by a different organism
Natural – baby becomes immune due to antibodies received from mother (placenta/breast milk)
Artificial – injected w antibodies from someone else