Vaccination practice exam questions

GTAC Biology Revision Series

Vaccination practice exam questions

SECTION A - Multiple-choice questions

Use the following information to answer questions 1 and 2

The graph below shows antibody levels for an individual over time. The antibodies measured were all

specific for a particular antigen.

Question 1 (1 mark) At which point on the graph did the individual first encounter the antigen that the antibodies target?

a) R

b) S

c) T

d) U

Question 2 (1 mark) Which of the following could have occurred at point T?


a) The individual received an initial dose of vaccine

b) The individual received a booster dose of vaccine

c) The individual encountered the antigen naturally

d) All of the above

SECTION B - Written responses

Question 1 (7 marks) Diphtheria is an infectious disease caused by the bacterium, Corynebacterium diphtheriae. The bacteria

attach to cells lining the upper respiratory tract and release a toxin that kills the infected cells. The dead

cells form a thick, grey film that covers the nose, throat, and tonsils. The film causes swelling and

interferes with the patient’s ability to breathe or swallow. If left untreated, it is potentially lethal.

1a. Diphtheria can be treated by administering an intravenous (IV) course of anti-toxin antibodies that

are isolated from horse plasma. State what type of immunity this is and explain why. (2 marks)

1b. Diphtheria can be prevented by vaccination. The Australian vaccination schedule recommends 5

doses of vaccine for children up to 4 years of age, followed by a booster dose at 11-13 years of age. The

booster dose enhances the immune response to diphtheria toxin. Explain how the booster shot leads to

an enhanced immune response. (2 marks)


1c. Fig.1 depicts the global vaccination coverage against diphtheria and the total number of diphtheria

cases reported since 1980.

Fig. 1. Vaccination coverage against diphtheria as a percentage of the world population and

worldwide reported cases of diphtheria between 1980 and 2016.

Referring to the graph, describe the concept of herd immunity and the effect of achieving herd

immunity on the prevalence of diphtheria cases. (3 marks)

Suggested responses begin on the next page.


Vaccination written responses: Suggested responses

In general, note the command terms: state, explain, referring to, describe.

1a. Diphtheria can be treated by administering an intravenous (IV) course of anti-

toxin antibodies that are isolated from horse plasma. State what type of

immunity this is and explain why. (2 marks)

Response you wrote:

Suggested response:

- Artificial passive immunity

- The antibodies are not produced by the patient’s own immune system but are introduced from

another source

1b. Diphtheria can be prevented by vaccination. The Australian vaccination

schedule recommends 5 doses of vaccine for children up to 4 years of age,

followed by a booster dose at 11-13 years of age. The booster dose enhances the

immune response to diphtheria toxin. Explain how the booster shot leads to an

enhanced immune response. (2 marks)

Response you wrote:

Tips for answering this question: The command term, “state” requires the student to answer with a

specific name for the type of immunity. Addition of the command term, “explain” invites the

student to give a detailed reason for their answer. The key observation to answer the question is

that the antibodies are introduced intravenously. For full marks, give the name and the reason.


Suggested response:

- Memory B cells are formed during the initial doses of vaccine

- The booster dose of vaccine activates the memory cells leading to more rapid production and

larger amount of antibodies

1c. Fig.1 depicts the global vaccination coverage against diphtheria and the total

number of diphtheria cases reported since 1980. Referring to the graph, describe

the concept of herd immunity and the effect of achieving herd immunity on the

prevalence of diphtheria cases. (3 marks)

Response you wrote:

Suggested Response:

- Herd immunity is achieved when 85% of the population is vaccinated against diphtheria

- At that level of vaccination, the spread of the pathogen between unvaccinated individuals is

limited

- Once herd immunity is achieved, the reported number of diphtheria cases approaches zero

Tips for answering this question: The command term, “explain” invites the student to give a cause

or a reason for a given observation. The explanation must provide a logical relationship between

the booster dose of vaccine and the enhanced immune response (in this case the production of

antibodies against diphtheria toxin). No other information is given in the question so the student

must access prior knowledge about the primary and secondary humoral immune response. For full

marks, refer to both the mechanism (memory cells) and the effect (faster and greater antibody

production).

Tips for answering this question: There are two command terms to take note of. The command

term “referring to” instructs the student to draw on evidence from the graph. The command term,

“describe” invites the student to provide a detailed picture of the concept of herd immunity. To

draw the two together, the student must link their understanding of herd immunity with the data in

the graph. For full marks, demonstrate an understanding of the concept of herd immunity,

demonstrate an understanding of the trend in the graph, and finally link the two together.

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Vaccination practice exam questions