A child receives a measles vaccination. After some time, the child becomes infected with the measles virus. The graph shows how the concentration of measles antibodies in the child’s bloodstream changes over this period. Which statement matches the information shown in the graph?
- AAfter the vaccination, the child produced memory cells.
- BThe child had passive immunity against measles.
- CThe measles virus contains antibodies.
- DThe vaccination failed to protect the child against measles.