Important Terms

3. treatment with a vaccine to produce immunity against a disease; inoculation.
4. a widespread occurrence of an infectious disease in a community at a particular time.
6. a quantity having direction as well as magnitude, especially as determining the position of one point in space relative to another.
8. a toxin or other foreign substance which induces an immune response in the body, especially the production of antibodies.
11. A bacterium or other microorganisms that can cause disease.
12. an individual animal, plant, or single-celled life form
13. a physical or mental feature which is regarded as indicating a condition of disease, particularly such a feature that is apparent to the patient.
14. the severity or harmfulness of a disease or poison.
16. a sudden occurrence of something unwelcome, such as war or disease.

1. a microorganism, especially a bacterium causing disease or fermentation.
2. (of a disease) prevalent over a whole country or the world.
5. liable to be transmitted to people
7. (of a disease or condition) regularly found among particular people or in a certain area.
9. An organism that lives in or on an organism of another species (its host) and benefits by deriving nutrients at the other's expense.
10. the ability of an organism to resist a particular infection or toxin by the action of specific antibodies or sensitized white blood cells.
15. an animal or plant on or in which a parasite or commensal organism lives.