vaccination

4. The body's defense system.
7. a small glass bottle, especially one containing liquid medicine for example vaccine
9. An extra dose
10. The upper limb where vaccines are often injected
11. World Health Organization
12. any small organism, such as a virus or a bacterium that can cause disease
13. Protection developed by the immune system after exposure to a vaccine
15. the act of putting a vaccine into a person's body
17. a substance that causes the body's immune system
18. disease occurring in almost the entire area or in almost the entire group of people
19. someone who does not agree with vaccinating people
20. a protein produced in the blood that fights diseases by attacking and killing harmful bacteria viruses etc

1. a measured amount of something such as vaccine
2. the study of how the body fights disease and infection
3. an extremely infectious disease that causes a fever, spots on the skin, and often death
5. a sign that someone should not continue with a particular medicine or treatment because it is or might be harmful
6. a medical condition in which the body temperature is higher than usual
8. a substance that is put into the body of a person or animal to protect them from a disease by causing them to produce antibodies
14. a person whose job is to care for people who are ill or injured, especially in a hospital
16. a thin metal pin