Across
- 1. A reaction of the immune system to a foreign substance which is usually harmless
- 2. The body's first line of defense against pathogens
- 5. A virus that mutates very quickly and damages an individual's immune system
- 7. Protein which neutralises pathogens
- 10. A non-living pathogen
- 11. Protein found on the surface of pathogens which antibodies can attach to
- 12. Living pathogens
- 13. An organism that causes disease
Down
- 1. Medicine used to help kill bacteria
- 3. A cell which can ingest and absorb pathogens
- 4. A type of immunity which occurs due to a large percentage of a population becoming immune
- 6. An injection of dead or weakened pathogen
- 8. A cell which produces antibodies
- 9. A type of immunity where an individual receives antibodies from an external source such as breast milk