Question 3

Read the following three statements and then answer the questionbelow.

• In 2019, the UK lost its ‘measles-free’ status.
• The basic reproduction number for measles (R0) is given asbetween 12 and 18, in different studies.
• The immunisation rate in the UK for measles dipped to a lowpoint in 2003 to 80% coverage and since then has risen to 91% in2019.

Question 5

1. Your friend is suffering from a fever and respiratory symptoms.She visits her GP and requests antibiotics. Explain why antibioticsmay not be appropriate for her infection.
2. Describe the effects of the overuse of antibiotics on thebacterial population in humans.
3. In order to distinguish between viral and bacterial infectionssome GPs now use a rapid point-of-care (POC) test for levels ofC-reactive protein (CRP). Explain the role of CRP in the immuneresponse and its relevance to use in this test.
4. In a hospital setting, treatment with antibiotics is a riskfactor for infection with Clostridium difficile. Explain whyClostridium difficile is commonly acquired in hospitals.

Explain, using calculations, the causal link between these threestatements and briefly discuss whether there is any prospect of theUK regaining its ‘measles-free’ status in the next 5 years.

Question 6

1. The cytokine IFNγ is produced by Th1 cells. Outline threedifferent functions of IFNγ in inflammation and/or the immuneresponse.
2. Name one cytokine that is produced specifically by Th2 cellsand state what effect it has on its target cell(s).
3. What advantage is there for the host in having two distinctpatterns of immune response, controlled by Th1 and Th2 cells?