During an outbreak of a viral disease, two people are exposed to the virus on day 0. Neither person has previously been infected with this virus, but one person has been vaccinated against it.
The concentration of antibodies against the virus in each person's blood is measured.
| Time after exposure (days) | Antibody concentration in person A (µg cm⁻³) | Antibody concentration in person B (µg cm⁻³) |
|---|---|---|
| 0 | 0.2 | 0.2 |
| 2 | 18.0 | 0.3 |
| 4 | 85.0 | 2.0 |
| 6 | 130.0 | 22.0 |
Explain which person was vaccinated and predict whether this person is likely to develop symptoms of the disease.
181 exam-style questions on OCR GCSE Biology 6.3 Monitoring and maintaining health, covering 6.3.1 Health and disease, 6.3.2 Interactions between diseases, 6.3.3 Spread of communicable diseases, 6.3.4 Common infections and diseases, 6.3.5 Physical plant defence responses, 6.3.6 Chemical plant defence responses, 6.3.7 Detecting and identifying plant diseases, 6.3.8 White blood cells and platelets, 6.3.9 Non-specific defence systems, 6.3.10 The immune system, 6.3.11 Monoclonal antibodies, 6.3.12 Vaccines and medicines, 6.3.13 Aseptic techniques, 6.3.14 Discovery and development of new medicines, 6.3.15 Causes of non-communicable diseases, 6.3.16 Treatments for cardiovascular disease, 6.3.17 Lifestyle factors and non-communicable diseases, 6.3.18 Cancer, 6.3.19 Stem cells in medicine, 6.3.20 Gene technology in medicine, and 6.3.21 The human genome and medicine. Each one has a worked solution and a mark scheme showing where the marks go.