Vaccine and Vaccination Flashcards
What is a vaccine?
suspension of antigens administered to induce immunity
Derived from microbial pathogens
What do vaccines contain?
- Preservatives and stabilizers- preserves antigens
- Specific antibiotics- inhibits bacterial/fungal growth
- Adjuvant- inhances immune response
Adjuvant
Delays the release of antigen from site of injection
Induces secretion of chemokines and leukocytes
Ex: Aluminum hydroxide, Saponin
Can be Depot, Particulate, or Immunostimulatory
Depot adjuvant
Slow removal of antigen results in prolonged immune response
Particulate adjuvant
Enhanced antigen presentation
Enhanced cytokine production by antigen presenting cells
Enhanced Th cell responses
Results in enhanced cell immunity and antibody production
Immunostimulatory adjuvants
Stimulates TLRs
Enhanced cytokine production by APCs
Enhanced Th cell responses
Results in enhanced cell immunity and antibody production
What is an ideal vaccine?
- Inexpensive
- Consistent in formation
- Stable
- Proper type of immune response
- Range of immunological epitopes
- Long lived immunity
- Immuno memory
- No adverse effects
Pros of live attenuated vaccines
- Rapid onset of immunity
- immunity after single dose
Cons of live attenuated vaccines
- Reversion to virulence
- Virulent in the immunocompromised
- Less stable in storage
Example of recombinant organism vaccine
- Johnson & Johnson COVID vaccine
- Oxford-AstraZeneca COVID vaccine
Recombinant organism vaccine
Infectious vaccine
Carrier organisms do not cause disease in vaccinated animals
Adjuvant not req.
Not revert to virulence
Ex j & j vax
Live attenuated vaccines
Infectious
Attenuated, intact + viable
Low level infection
Does not induce significant tissue pathology or clinical disease
Marker vaccines
Infectious
Permits discrimination between vaccine and exposure immune response
AKA DIVA vaccine
Ex: bovine rhinotracheitis with deletion of surface glycoprotein E gene
Killed whole organism vaccines
Non infectious vaccine
Antigenically intact
Unable to replicate, induce pathology or clinical disease
Chemical killing- formalin, alcohol, alkylating agents
Subunit vaccine
Non infectious
uses structural proteins or metabolites of an organism
Ex: purified proteins, synthetic peptides, recombinant proteins/ plasmid used
Non infectious vaccines?
- Killed whole organisms vaccine
- Subunit vaccine
- Naked DNA vaccine
- mRNA
Naked DNA vaccine
Non infectious
Gene from a pathogen is cloned to a plasmid, delivered directly into the animal
Plasmids transfect APCs for antigen presentation
mRNA vaccines
Non infectious
mRNA of pathogen is made and delivered directly into recipient
Processed in APC for antigen presentation
Ex: Pfizer COVID vax
Vaccination
Artificial induction of immunity to protect from infectious diseases
Active or passive
Passive vaccination
- antibodies administered
- Particular antigen
- Immediate protection
- Temporary protection, hypersensitive rxn
Inhibits endogenous Ab response
Ex: Tetanus antitoxin, anti-venoms, mAb to SARS-CoV-2
Active vaccination
Antigens administered
Immune response induced recipient
Humoral/Cell- mediated responses
Immuno memory
Protection levels of active vaccination
- Strong protective immunity- no infection
- Infected but clinically well
- Infected with reduced/mild form of disease
- Failure- no protection
Methods of vaccine delivery
- Injection
- Intranasal
- Needle-free
Examples of adverse effects
- Type 1 hypersensitivity- Facial or periorbital edema, pruritus
- FISS (Feline Injection Site Sarcoma
