HSC Biology Sample Marked Response: Vaccination and Immunity

Sample question

Describe how vaccination leads to immunity against a disease. (4 marks)

Partly correct student answer

Vaccines put a small amount of disease into the body so the immune system can fight it. Then if you get the disease later, your body already knows what to do.

What is missing

• The answer should refer to antigens rather than a vague 'small amount of disease'.
• It should explain production of specific antibodies and memory cells.
• It should link memory cells to a faster secondary immune response.

Stronger answer

Vaccination exposes the immune system to an antigen from a pathogen without causing the full disease. Specific lymphocytes respond by producing antibodies and memory cells. If the same pathogen enters the body later, memory cells trigger a faster and stronger immune response, so the pathogen is controlled before disease develops.