Vaccines and Vaccination

Question 1

What is a vaccine

Answer 1

A vaccine is a suspension of antigens that is administered to induce immunity
Currently majority of vaccines derive from microbial pathogens for controlling infectious diseases

Question 2

Vaccines contain

Answer 2

Protective antigens
Preservatives and stabilizers- preserving Ag
Specific antibiotics- inhibiting bacterial and fungal growth
Adjuvant-enhancing the immune response to Ag

Question 3

Adjuvant

Answer 3

Delay the release of Ag from the site of injection
Induce the secretion of chemokines by leukocytes
Aluminum hydroxide, saponin etc

Question 4

Ideal Vaccine

Answer 4

Inexpensive
Consistent in formation-minimal variations (batch by batch)
Stable
Proper type of immune response
Range on immunological epitopes
Long-lived immunity
Immunological memory
No adverse effects

Question 5

Live attenuated vaccines

Answer 5

Attenuated, yet intact and viable organism
Low-level infection
Do not induce significant tissue pathology or clinical disease

Question 6

Live attenuated vaccines. Pros and cons

Answer 6

Pro:
Rapid onset of immunity
Sustained immunity after single dose
Cons:
Potential for reversion to virulence
Virulence in the immunocompromised
Less table in storage

Question 7

Recombinant organism vaccine

Answer 7

Carrier organisms do not cause disease in vaccinated animals
Adjuvant not required
Not revert to virulence

Question 8

Marker Vaccines

Answer 8

A marker vaccine permits discrimination between a vaccinal and an exposure immune response (differentiating infected from vaccinated animals vaccine)

Question 9

Killed whole organism vaccines

Answer 9

Antigenically intact
Unable to replicate or induce pathology or clinical disease
Chemical killing-formalin, alcohol, or alkylating agents

Question 10

Attenuated live pros and cons

Answer 10

Pros:
Rapid onset of immunity 
May immunize others in population
Sustained immunity
Cons:
Possible reversion to virulence
Virulent in the compromised
Less stable in storage
May cause immune suppression

Question 11

Inactivated pros and cons

Answer 11

Pros:
Safe
No interference with other vaccines
Stable in storage
Cons:
Slow onset of immunity
Multiple boosters required
Adjuvant-adverse effects
Reduced degree of protection vs the live

Question 12

Subunit Vaccines

Answer 12

Containing immunological structural proteins or metabolites of an organism
Purified proteins
Synthetic peptides
Recombinant proteins

Question 13

Naked DNA vaccines

Answer 13

A gene of interest from a pathogen is cloned to a plasmid, which is delivered directly into the animal
The plasmids transfect host including APCs; the pathogen gene is expressed and processes in APC for antigen presentation

Question 14

Vaccination

Answer 14

Immunization
Artificial induction of immunity to protection from infectious diseases
Active and passive immunization

Question 15

Passive Immunization

Answer 15

Preformed antibodies administered
To particular antigen
Immediate immunological protection
Temporary protection
Tetanus antitoxin; antivenoms

Sensitize the recipient for a hypersensitive reaction
Inhibit the endogenous Ab response of the recipient

Question 16

Active Immunization

Answer 16

Antigens administered
Immune responses induced in recipient
Humoral/cell-medicated responses
Immunological memory
Protection levels:
-strong protective immunity-no infection
-infected, but clinically well
-infected with much reduced and mild form of disease
-failure-no protection

Question 17

Method of Vaccine delivery

Answer 17

injection vaccination
intranasal vaccination
needle-free vaccination

Question 18

Adverse effects

Answer 18

Type I hypersensitivity: facial or periorbital edema, pruritus

Feline injection site sarcoma: surgical removal challenging. poor prognosis