1. Chapter 19, Section 3 Preventing Infectious Disease Wednesday, April 28, 2010 Pages 605 -- 609

2. Objectives Define and explain active immunity. Define and explain passive immunity. Identify some strategies for staying healthy.

3. Vocabulary Words Immunity Active immunity Vaccination Vaccine Passive immunity Antibiotic

4. What is Immunity? Immunity is the body’s ability to destroy pathogens BEFORE they can cause disease. There are two types of immunity. –Active –Passive

5. Active Immunity Active immunity is when your body produces antibodies to fight virus antigen. The next time your body is invade by the same virus antigens, your immune system will be able to produce these antibodies quickly so you don’t become sick.

6. Active Immunity -- cont’d Active immunity is produced by the cells of a person’s immune system as part of immune response. Once you’ve been sick, your body remembers the pathogen’s antigens. Your immune system’s “memory” will start the immune response quickly. Active immunity usually lasts for many years and sometimes it lasts for life.

7. Vaccination Vaccination is a process by which harmless antigens are deliberately introduced into a person’s body to produce active immunity. Vaccine is the substance used in a vaccination. –It’s made up of pathogens that are weakened or killed but can still trigger the immune system.

8. Passive Immunity This type of immunity is given to a person who is already affected. This is usually in the form of an injection because the person’s own immune system did not make them. Passive immunity comes from a source other than from the person’s own body. This type of immunity does not last for a long time.

9. Staying Healthy Most people stay healthy through vaccinations. When sick, medications can help. Antibiotics is a chemical that kills bacteria or slows their growth without harming body cells.

10. Review Questions What is active immunity? How is it produced? How is passive immunity produced? How is passive immunity different from active immunity? Identify four things that you can do that will help you avoid catching an infectious disease.

11. Homework Workbook 19.3 (4/29)