Outline6 marksChallenge
The table below shows the relative antibody concentration in the blood of a human volunteer following an initial injection (day 0) with a harmless novel antigen (antigen X), and a second injection (day 28) with the same antigen.
| Day | Antibody concentration (arbitrary units) |
|---|---|
| 0 | 0 |
| 3 | 0 |
| 5 | 2 |
| 7 | 8 |
| 10 | 20 |
| 14 | 30 |
| 21 | 15 |
| 28 | 5 (second injection given) |
| 31 | 15 |
| 35 | 60 |
| 42 | 50 |
| 56 | 30 |
Outline the sequence of events that lead to the differences observed between the primary and secondary immune responses. In your answer, refer to the roles of macrophages, B-lymphocytes (including plasma cells), T-helper cells, T-killer cells, and memory cells.