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Chapter 18. Practical Applications of Immunology. Vaccine History. Variolation: Inoculation of smallpox into skin (18 th century) Vaccination: Inoculation of cowpox into skin Herd immunity results when most of a population is immune to a disease.
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Chapter 18 Practical Applications of Immunology
Vaccine History • Variolation: Inoculation of smallpox into skin (18th century) • Vaccination: Inoculation of cowpox into skin • Herd immunity results when most of a population is immune to a disease.
Principal Vaccines Used in the United States to Prevent Bacterial Diseases in Humans • DtaP • Diphtheria: Purified diphtheria toxoid • Pertussis: Acellular fragments of B. pertussis • Tetanus: Purified tetanus toxoid • Meningococcal meningitis: Purified polysaccharide from N. meningitidis • Haemophilus influenzae type b meningitis: Polysaccharides conjugated with protein • Pneumococcal conjugate vaccine: S. pneumoniae antigens conjugated with protein
Principal Vaccines Used in the United States to Prevent Viral Diseases in Humans • Smallpox: Live vaccinia virus • Poliomyelitis: Inactivated virus • Rabies: Inactivated virus • Hepatitis A: Inactivated virus • Influenza: Inactivated or attenuated virus • Measles: Attenuated virus • Mumps: Attenuated virus • Rubella: Attenuated virus • Chickenpox: Attenuated virus • Hepatitis B: Antigenic fragments (recombinant vaccine)
Precipitation Reactions • Involve soluble antigens with antibodies Figure 18.3
Agglutination Reactions • Involve particulate antigens and antibodies • Antigens may be: • On a cell (direct agglutination) • Attached to latex spheres (indirect or passive agglutination) Figure 18.4
Antibody Titer • Is the concentration of antibodies against a particular antigen Figure 18.5
Hemagglutination • Hemagglutination involves agglutination of RBCs. • Viral hemagglutination inhibition tests for antibodies by the antibodies' ability to prevent viruses from agglutinating RBCs. Figure 18.7
Neutralization Reactions • Eliminate the harmful effect of a virus or exotoxin Figure 18.8b
Complement Fixation Figure 18.9.1
Complement Fixation Figure 18.9.2
Fluorescent Antibody Techniques (Direct) Figure 18.10a
Fluorescent Antibody Techniques (Indirect) Figure 18.10b
Enzyme-Linked Immunosorbent Assay(Direct ELISA) Figure 18.12a
Enzyme-Linked Immunosorbent Assay (Indirect ELISA) Figure 18.12b
Serological Tests Figure 18.13
Serological Tests • Direct tests detect antigens (from patient sample) • Indirect tests detect antibodies (in patient's serum)
Serological Tests • Agglutination: Particulate antigens • Hemagglutination: Agglutination of RBCs • Precipitation: Soluble antigens • Fluorescent-antibody technique: Antibodies linked to fluorescent dye • Complement fixation: RBCs are indicator • Neutralization: Inactivates toxin or virus • ELISA: Peroxidase enzyme is the indicator