Do Now Quiz 1. What are antigens and where are they found? 2. What are antibodies and where are they made? 3. Explain the relationship between antigens and antibodies.

LO: SWBAT describe how our body becomes resistant to disease DN: Quiz #2 HW: Read page , page 1053# 29,30,40 Quiz Friday

Bioterrorism Fatal hemorrhagic smallpox in a twelve-year-old girl, 1970s, Bangladesh. A genetically - engineered strain of smallpox might produce unusual symptoms such as these. Here, the eyes are filled with blood, and blood blisters form in the mouth and inside the body. How can we protect ourselves? vaccines Today there is mounting concern about the threat of a bioterrorist attack using smallpox -- so much concern that in October 2001 the American government decided to order enough vaccines to protect every U.S. citizen. Smallpox has a fearsome reputation, having killed more people in history than any other infectious disease.

What is a vaccine? a weakened or dead form of a pathogen so it is no longer harmful, but it still has the antigens present. Weakened Pathogen Antigen Antibody These antigens trigger an immune response.

How was the first Vaccine developed? English physician Edward Jenner developed an inoculation against smallpox in Armed with the knowledge that milkmaids who had been exposed to cowpox, a relatively mild affliction, didn't come down with smallpox, Jenner intentionally infected an eight- year-old boy with cowpox. Two months later he infected the boy again, this time with smallpox. As Jenner expected, the child didn't come down with the disease -- he was immune.

Vaccines depend on the “memory” of the immune system. First response: slow and weak Second Response (to same pathogen): Quicker and stronger ** After the first response, the immune system “remembers” specific pathogens by leaving behind WBCs that protect the body for years (memory cells).

How do scientists make vaccines? accines.htmlhttp:// accines.html 1)Obtain pathogen 2)Weaken/kill pathogen 3)Inject altered pathogen (vaccine) into organism. 4)Body responds to antigens by making antibodies & having WBCs attack invader. 5) Some WBCs specific for this pathogen remain in the body to protect the organism from future attacks.

What happens when you get invaded by the real pathogen? Memory cells (WBC specific for that pathogen) are already present and will multiply quickly and destroy the invader before it has the chance to cause the disease. Memory Cells

What is immunity? The ability of a person who once had a disease to be protected from getting the same disease again.

Immune response Antibody Concentration Time First exposure Second exposure Interval between exposures Vaccine Real Pathogen Vaccine Real Pathogen First exposure Second exposure Interval between exposures

Vaccines

Active vs. Passive immunity Active Immunity Your body makes antibodies to fight pathogen Long lasting Ex: vaccine, getting sick with the pathogen Passive Immunity You get antibodies from a different organism- your body doesn’t make the antibodies Short lasting Ex: injection of antibodies, mother to child

How are these two types of immunity different?