Exam 3 (Vaccines) Flashcards
Vaccine
Product developed to stimulate immunity against dz
Vaccination
Injection of vaccine to induce immunity against specific dz
Immunization
Creating immunity by introducing a killed/modified infectious agent which allows body to create antibodies
Edward Jenner
1796- vaccinated people against small pox by scratching them with cow pox
“Father of immunology”
Why Do We Vaccinate
- Protect individuals
- Protect populations-herd immunity
- Protect against transmission of zoonotic dz
- Health benefits for pets?
- Decrease dz burden
6 Types of Vaccines
Modified live Killed (inactivated) Polyvalent Subunit Heterologous DNA based
Modified Live Vaccine
Contains a live organism
Modified so it is unable to cause the dz in the body
Example: Distemper
Advantages of Modified Live Vaccine
More rapid protection Produces strong mediated immunity Longer lasting immunity No adjuvant required Less expensive to produce
Disadvantages of Modified Live Vaccine
Must handle carefully to maintain viability
Potentially reverts to former virulence
May cause dz in immunocompromised animals
Potential abortion or fetal abnormalities
Killed Vaccine
Organisms have been killed/inactivated by chemical/physical agents
Cannot replicate
Used in conjunction with an adjuvant
Example: Rabies vaccine
Adjuvant
- Substance that is added to an inactivated (killed) vaccine to stimulate an inflammatory immune response
- Increases response to antigen by stimulating immune system, combined with killed vaccine, they stimulate a protective immune response
Advantages of Killed Vaccine
No possibility of reversion to virulence
Won’t cause abortion or abnormalities
Remains stable longer in storage and when handled
Disadvantages of Killed Vaccine
Requires an adjuvant for maximum immune response
Greater chance of hypersensitivity reaction
Not as immunogenic as MLV
Requires more frequent revaccination
Bacterin
Killed vaccine made up of bacteria
Example: Leptospirosis
Polyvalent Vaccine
Killed vaccine that contains 2 or more antigens from related organisms
Example: Pasturella multicida A and D
Leptospirosis (4 strains)
Subunit Vaccine
Vaccine that is made up of parts of the virus (less reactive)
Example: FeLV (Feline Leukemia Virus)
DNA Based
- Type of subunit vaccine
- Gene or DNA that produces immuno protective proteins on the pathogen are removed and inserted into an avirulent vector (canarypox)
- These vaccines are genetically engineered to provide a safer alternative to MLV –> There is no chance that they will revert to a virulent form
Example: West Nile Equine Vaccine