Immunity

4. Sickness, illness, or loss of health; conditions that make people unhealthy.
6. Worldwide disease outbreak that spreads across countries and continents.
10. A disease or period of sickness affecting the body or mind.
12. Protection against a disease.
13. Tiny one-celled organisms in the environment. While not all bacteria are harmful, some cause disease.
15. The process of being made immune or resistant to an infectious disease, typically by a vaccine.

1. A protein found in the blood that is produced in response to foreign substances (e.g., bacteria or viruses) invading the body.
2. Foreign substances (e.g., bacteria or viruses) in the body that can cause disease. The presence of antigens in the body triggers an immune response, usually the production of antibodies.
3. Consistently present but limited to a particular region, usually in low levels.
5. A disease that is suddenly spread through a large number of people within a community, population, or region greater than normally expected.
7. A substance that produces immunity and prevents the spread of disease.
8. A tiny organism that multiplies within cells and causes disease in people, other animals, and plants.
9. In a state of normal functioning; free from disease.
11. Action taken to decrease the chance of getting a disease or condition.
14. Literally "against-virus;" a medicine capable of destroying or weakening a virus.