A child receives a measles vaccination. Some time later, the child becomes infected with the measles virus. The graph illustrates the concentration of measles antibodies in the child’s bloodstream over this period. Which statement agrees with 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.