A volunteer in a clinical trial receives a primary vaccine dose at day 0 and a booster dose at day 40. The graph below shows the changes in the antibody concentration of their blood over a 60-day period.
From the clinical records:
- At day 10, the antibody concentration reaches its first peak of 30 AU30\text{ AU}30 AU.
- At day 40, immediately prior to the booster injection, the antibody concentration has declined to 6 AU6\text{ AU}6 AU.
- At day 45, the concentration reaches its second peak of 258 AU258\text{ AU}258 AU.
Using this data and the graph:
a.[3]
Calculate the percentage increase in peak antibody concentration from the first peak to the second peak.
b.[5]
Calculate and compare the mean rate of increase in antibody concentration (in AU/day\text{AU}/\text{day}AU/day) from the time of injection to the peak concentration for both:
- the primary dose (from day 0 to day 10)
- the booster dose (from day 40 to day 45)