Across
- 3. virus which has caused the most recent pandemic
- 4. protected against a disease
- 5. a reaction by the body to a disease
- 7. the body's ability to protect itself against a disease
Down
- 1. a substance used to stimulate the production of antibodies that provide immunity against a disease
- 2. large part of a population is immune to a disease
- 6. a disease causing organism