Vaccinations

Purpose Vaccination is a method of giving an antigen to stimulate the immune response through active immunity Stimulates the proliferation of T and B cells, resulting in the formation of effector and memory cells – stimulates acquired immunity without disease pathology

Types of Vaccines Live Unattenuated– unaltered pathogen given Rare Ex. Small pox vaccine – use live, unaltered cow pox vaccine https://www.youtube.com/watch?v=yqUFy-t4MlQ

Live Attenuated – altered/weakened to remove virulence Should not be given to immunocompromised individuals MMR, nasal flu, chicken pox, oral polio, yellow fever, rabies Less need for boosters than killed vaccines Can be administered in a variety of ways

Killed/Inactivated – use chemicals or heat to kill and are not infectious Polio shot, flu shot, cholera, pertussis (whooping cough) Usually require booster shots Safe to give immunocompromised individuals

Toxoids – stimulates body to produce antibodies to toxins produced by bacteria rather than the bacteria itself Diptheria, tetanus https://www.youtube.com/watch?v=ZVPmQsknlH8 https://www.youtube.com/watch?v=IDWOxh2lCX4

Recombinant DNA Put a gene that codes for antigens of a pathogenic bacteria into a non-pathogenic microbe, then extract the antigens Ex. Hepatitis B

Conjugation Many bacteria have a polysaccharide coat on the outside These vaccines combine a protein with the polysaccharide – the protein induces the immune system to make antibodies that recognize the polysaccharide Ex. Meningitis, pneumonia

Risks In live vaccines, there is a low risk that the vaccine will cause the disease (more likely in immunocompromised individuals) Occasionally a vaccine can overstimulate the immune system Some vaccines are made with ingredients that may cause allergic reactions (egg is most common)

Herd Immunity If most of the people in a community have been immunized and are protected from an infectious agent, the chance of a susceptible (i.e. unimmunized) individual contacting an infected individual is so low that the susceptible person is not likely to become infected.