Vaccination (year 2)

Question 1

what is passive immunisation?

Answer 1

provides rapid protection by administration of specific antibodies

Question 2

when may passive immunisation be used?

Answer 2

accidental exposure of susceptible animals to pathogens

supportive therapy for immunocompromised animals

Question 3

how long does protection last with passive immunisation?

Answer 3

short term protection

Question 4

what is active immunisation?

Answer 4

introduction of microbial products to induce long term protective immunity and memory with a rapid secondary response

Question 5

do vaccines always trigger an antibody response?

Answer 5

no, if the virus is intracellular it generates a strong CD8 T cell response instead to obliterate infected cells

Question 6

what are the two routes of active immunisation?

Answer 6

systemic and mucosal (local)

Question 7

how are systemic vaccines administered?

Answer 7

usually intramuscular or subcutaneous

Question 8

why are systemic vaccines administered subcutaneously?

Answer 8

the vaccine is retained in this space causing discomfort which triggers a stronger immune response
skin also contains specialised cells called langerhans which capture and process antigens in skin which then travel to the lymph nodes which stimulates a very effective T cell response

Question 9

why is it significant that the antigen is taken to lymph nodes when injected subcutaneously?

Answer 9

means it travels long way meaning there is plenty of time to process antigens and present the epitopes in MHC complexes

Question 10

how are mucosal vaccines administered? give examples

Answer 10

orally - salmonella
intranasally - Bordetella bronchiseptica
aerosol - Newcastle disease

Question 11

give a positive and negative of mucosal vaccines

Answer 11

positive - responds quicker

negative - must survive inhospitable environment

Question 12

what are adjuvants and when are they used?

Answer 12

non-specific enhancers of immune responses to non-living vaccines used when the vaccine is weak

Question 13

give two ways an adjuvant may function

Answer 13

enabling slow release of a vaccine

non-specifically stimulating the immune system

Question 14

what are some examples of adjuvants?

Answer 14

aluminium/calcium salts
microbial products
synthetic agents (carbopol)
exogenous cytokines (IL-2)

Question 15

what are the advantages of a live vaccine?

Answer 15

fewer doses needed
adjuvants not needed
less chance of hypersensitivity
cheap
induces interferon

Question 16

what are the advantages of an inactivated vaccine?

Answer 16

stable
unlikely to cause disease
unlikely to contain contaminating organisms

Question 17

what are the disadvantages of inactivated vaccines?

Answer 17

need more doses
less immunogenic
need adjuvants

Question 18

do inactivated vaccines give better antibody of cell mediated immune responses?

Answer 18

antibody

Question 19

give some examples of an inactivated vaccine

Answer 19

killed
inactivated toxin
subunit vaccine (influenza H/N)
subcellular fragments
specific recombinant gene products
DNA