vaccines

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VACCINES https://www.youtube.com/watch?v=rb7TVW77ZCs

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Page 1: VACCINES

VACCINES

https://www.youtube.com/watch?v=rb7TVW77ZCs

Page 2: VACCINES

HISTORY OF VACCINES• Variolation to Vaccination

• Variolation• Innoculation of smallpox into skin

• Vaccination• Edward Jenner developed the modern practice of

vaccination when he inoculated people with cowpox virus to protect them against smallpox.

Page 3: VACCINES

HOW DO VACCINES WORK?• “Trick” human immune system into producing antibodies

or immune cells

• Induce protection against real disease-causing microbes

• Do not cause illness but cause production of T cells and Antibodies

Page 4: VACCINES

WHAT DO WE WANT TO ACHIEVE WITH VACCINES?

• Herd Immunity

• Large proportion of group is resistant whole group is resistant

• Results from effective vaccination programs (90% vaccinated no spread of disease)

Page 5: VACCINES

IMMUNOLOGIC MEMORY

Page 6: VACCINES

KILLED INACTIVATED VACCINES• Also fight viruses

• No danger of infection• Made by inactivating or killing the virus during the process of

making the vaccine• Killed by treatment with heat or chemicals

• Does not stimulate cell mediated immunity

• Usually need booster vaccines

• Examples• Salk Polio Vaccine and Rabies Vaccine

Page 7: VACCINES

TOXOID VACCINES• Prevent diseases caused by bacteria that produce toxins (poisons) in

the body

• Some bacteria cause disease by producing toxins that invade the bloodstream

• Toxins are weakened so they can’t cause illness

• Toxoids

• The immune system will learn how to fight off the natural toxin after receiving the vaccine with a toxoid

• Examples

• Diphtheria• Tetanus and Pertussis (DTaP vaccine- contains diphtheria and tetanus

toxoids)

Page 8: VACCINES

SUBUNIT VACCINES• Only use part of a bacteria or virus

• Produce effective immune response without causing separate & potentially harmful immune reactions to the many antigens carried on microbe

• Examples

• DTaP vaccine (The pertussis component is an example of a subunit vaccine)

• Typhoid• Hepatitis B

Page 9: VACCINES

NON-INFECTIOUS VACCINES

The first three vaccines named in these notes are considered to be non-infectious

- Will make B-memory cells and T-helper memory cells = good antibody response

-Will not make memory killer T cells

-Booster vaccines usually needed

Page 10: VACCINES

LIVE ATTENUATED VACCINES• Fight viruses

• Closest to natural infection

• Contain a version of the living virus that has been weakened so that it does not cause serious disease in people with healthy immune systems

• Not everyone can receive them• Children with weakened immune systems (ex: patients

undergoing chemotherapy)

• Examples

• Sabin Polio Vaccine (not currently recommended)• Measles, Mumps, and Rubella Vaccine (MMR) • Varicella (chickenpox) Vaccine

Page 11: VACCINES

LIVE ATTENUATED VACCINES

-Makes memory cells: B-cells, T helper and Killer T cells- Usually life-long immunity

Some viral shedding: can produce disease in immunocompromised host

Page 12: VACCINES

CONJUGATE VACCINES

• Fight different type of bacteria

• Bacteria have antigens (Ag) with an outer coating of sugar-like substances called polysaccharides

• Coating disguises the Ag• Coat isn’t recognized by immature immune systems of young infants

therefore there is no response to it

• These vaccines link together proteins or inactivated toxins from a 2nd organism to bacteria’s outer coat

• Enables baby's immune system to respond to combined vaccine & produce antibodies

• Causes immune response against disease-causing bacteria

• Examples

• Haemophilus influenzae type B (Hib vaccine)

Page 13: VACCINES

SAFETY OF VACCINES

• Benefits of vaccines far outweigh their risks

• The American Academy of Pediatrics, the Centers for Disease Control and Prevention, and the Institute of Medicine all conclude that the benefits of vaccines outweigh their risks

• Thimerosal is a preservative that was found in most vaccines in the past. But now:

• Only one third of flu shots still have thimerosal• NO other vaccines commonly used for children or adults

contain thimerosal• Research done over many years has NOT shown any link

between thimerosal and autism, or other medical problems

Source: http://www.nlm.nih.gov/medlineplus/ency/article/002024.htm

Page 14: VACCINES

Source: CHAPTER 22 VACCINATION

Page 15: VACCINES