A vaccine is available against a virus that is spread through the air. The table shows the percentage of the population that had been vaccinated against this virus, and the number of new cases of the disease, in one country in four different years.
Table: The percentage of the population vaccinated against a virus and the number of new cases of the disease it causes, in one country in four different years
| Year | Percentage (%) of the population vaccinated | Number of new cases in the year |
|---|---|---|
| 2018 | 20 | 4800 |
| 2019 | 45 | 2600 |
| 2020 | 70 | 900 |
| 2021 | 92 | 110 |
Describe the relationship between the percentage of the population vaccinated and the number of new cases each year. Use data from the table.
Explain how vaccinating a large percentage of the population reduces the number of new cases in people who have not been vaccinated.
In 2022 the percentage of the population vaccinated fell to 60%. Predict the effect this would have on the number of new cases in 2022. Give a reason for your answer.
The data in the table cannot prove that vaccination caused the fall in the number of new cases. Suggest one other reason why the number of new cases may have fallen.
176 exam-style questions on AQA GCSE Biology 3.1 Communicable diseases, covering 3.1.1 Communicable (infectious) diseases, 3.1.2 Viral diseases, 3.1.3 Bacterial diseases, 3.1.4 Fungal diseases, 3.1.5 Protist diseases, 3.1.6 Human defence systems, 3.1.7 Vaccination, 3.1.8 Antibiotics and painkillers, and 3.1.9 Discovery and development of drugs. Each one has a worked solution and a mark scheme showing where the marks go.