A survey in a town recorded whether people had been vaccinated against a disease and whether they developed the disease during one winter.
| Group | Number of people | Number who developed the disease |
|---|---|---|
| Vaccinated | 500 | 30 |
| Unvaccinated | 250 | 40 |
Calculate the difference between the percentages of people who developed the disease in the two groups.
Explain what the results suggest about vaccination.
87 exam-style questions on Edexcel GCSE Biology 5.3 Immune system and medicines, covering 5.3.1 The specific immune system, 5.3.2 Response to immunisation, 5.3.3 Advantages and disadvantages of immunisation, 5.3.4 Antibiotics and bacterial infections, 5.3.5 Aseptic techniques in culturing, 5.3.6 Cross-sectional areas of cultures, 5.3.7 Stages of developing new medicines, and 5.3.8 Production of monoclonal antibodies. Each one has a worked solution and a mark scheme showing where the marks go.