Vaccination

Question 1

What is the difference between active and passive immunity?

Answer 1

Passive- provides rapid protection with administration of specific antibodies (colostrum)- short term
Active- Immunisation with microbial products that induce long term protection (vaccine)

Question 2

How is active immunity solutions usually administered?

Answer 2

Systemic

Mucosal (local)

Question 3

How does subcutaneous vaccine stimulate an immune response?

Answer 3

Skin contains specialties monocyte derived epidermal cells- langerhan cells, precursor of dendritic cells
They capture and process antigens in skin, travel to lymph node
Become follicular dendritic cells, stimulate T cells effectively

Question 4

What are adjuvants and how do they work and what are some examples?

Answer 4

Non-specific enhancers of immune responses to non-living vaccines
Function by enabling slow release of vaccine antigens into the body, stimulating the immune system non-specifically
(aluminium and calcium salts, microbial products, synthetic agents, exogenous cytokines)

Question 5

What are the pros of living vaccines and what’re they made from?

Answer 5

Few inoculating doses required
Adjuvants unnecessary 
Less chance of hypersensitivity 
Induction of interferon
Relatively cheap

Question 6

What are the pros of inactivated vaccines?

Answer 6

Stable on storage
Unlikely to cause disease through residual virulence
Unlikely to contain contaminating organisms

Question 7

What are the pros and cons of dead vaccines?

Answer 7

Safer then live
Less immunogenic

Need administration more often
Not effective by natural infection route
Give better antibody responses compared with CMI
Need adjuvants for effective immunity

Question 8

What can inactivated antigens contain?

Answer 8

Killed organisms
Inactivated toxins
Subunit vaccines (recombinant antigens)
Subcellular fragments 
Specific recombinant gene products 
DNA itself

Question 9

How are live attenuated vaccines produced?

Answer 9

Mutants selected in vitro to reduce virulence but retain antigenicity
Mutants identified and selected from natural field strains
Live ‘vectors’ into which are inserted specific gene products

Question 10

What are the main functions of vaccines?

Answer 10

Prevent disease

Stop shedding of infectious virus to cohorts