Describing vaccination evidence means comparing the numbers for vaccinated and unvaccinated groups in careful words. Quote figures, say which group is higher, and stop short of claiming more than the data can support. This is a science reading skill, not medical advice.
It builds on the immune response and belongs to disease and defence concepts.
How do you describe a table well?
Use three moves in this order: describe, quote, explain.
- Describe the pattern in one sentence: which group has fewer cases.
- Quote figures from the table, such as percentages or case counts.
- Explain using biology only if the question asks, for example memory cells.
When groups have different sizes, compare percentages or rates, not raw counts, so the comparison is fair.
Worked example
A school recorded how many students caught a disease during one term. The data are invented for practice.
| Group | Number of students | Number who caught the disease |
|---|---|---|
| Vaccinated | 2000 | 12 |
| Not vaccinated | 2000 | 96 |
Question: Use the table to compare the two groups.
Step 1, percentage vaccinated: 12 ÷ 2000 = 0.006, so 0.6%.
Step 2, percentage not vaccinated: 96 ÷ 2000 = 0.048, so 4.8%.
Step 3, compare: 4.8 ÷ 0.6 = 8, so the unvaccinated group had 8 times the proportion of cases. Check: 0.6 × 8 = 4.8.
Step 4, careful wording: fewer vaccinated students caught the disease, but 12 vaccinated students still did, so the vaccine did not stop every case.
Answer: 0.6% of vaccinated students and 4.8% of unvaccinated students caught the disease, which is 8 times the proportion in the unvaccinated group.
The mistake to watch for
A common slip is to claim a vaccine works perfectly.
Mistaken answer: “The vaccine stops everybody from getting the disease.”
The student ignored the 12 vaccinated cases in the table.
The correction is to write only what the data support. “Fewer vaccinated students caught the disease” is correct. Another careful point is that one school table does not show why the groups differ, because other factors such as age or earlier exposure may also differ between them.
Check yourself
Try these, then open each answer.
1. In another class, 500 vaccinated students had 5 cases and 500 unvaccinated students had 40 cases. Give both percentages.
Show answer
Vaccinated: 5 ÷ 500 = 0.01, so 1%. Unvaccinated: 40 ÷ 500 = 0.08, so 8%.
2. Why should you compare percentages and not raw numbers when the group sizes differ?
Show answer
A larger group will have more cases simply because it has more people. Percentages remove the effect of group size and make the comparison fair.
3. Suggest one reason a table of cases cannot on its own prove that a vaccine caused the difference.
Show answer
The groups may differ in other ways, such as age or how much they were exposed to the pathogen. Without controlling these factors, the difference cannot be attributed to the vaccine alone.
Where this leads next
Populations can also change in response to medicines. Continue to discussing antimicrobial resistance without treatment advice, then try the mixed practice set.
Students who find data questions slip between over-claiming and saying too little can practise the balance in online one-to-one Biology tuition.