1. IMMUNE SYSTEM III
PP &

3. VACCINES
Using a weakened form of a pathogen to initiate an immune response to create memory cells

4. ALLERGIES Allergens: cause allergies
Over-reaction of the immune system to a harmless invader)

5. IMMUNE DISORDERS
Autoimmune: The immune system attacks their own body cells as though they were pathogens.
EX. Rheumatoid Arthritis

6. Immune deficiency:  the immune system's ability to fight infectious disease is compromised or entirely absent
HIV: human immunodeficiency virus
AIDS (acquired immune deficiency syndrome): weakened immune system caused by the infection of HIV
HIV ≠ AIDS

8. HIV Caused by a retrovirus 1. Enzymes to transcribe its RNA to DNA
2. New DNA inserted into host cell’s DNA
3. Host cell now makes proteins to assemble more HIV viruses

9. AIDS

10. Transmission: fluid containing the virus or cells with the virus (blood, sexually, breast-feeding)
Course of the disease
Phase I: (asymptomatic) few or no symptoms
Phase II: worsening of symptoms
Phase III: T-cell count goes below cells/mL (normal )
People with AIDS die from opportunistic infections (diseases that only strike because of a weakened immune system)