A child receives a vaccination against measles. Some time later, the child becomes infected by the measles virus. The graph indicates 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.