Immune therapies

Question 1

why would you want to manipulate the immune response?

Answer 1

• to promote protective immune responses - vaccinations, fight tumours, treat immunocompromised pts
• to suppress unwanted immune responses - chronic inflammation, autoimmunology, allergy

Question 2

why do we vaccinate?

Answer 2

• most effective stategy to prevent disease
• promote human health
• primary aim to induce immunity in individuals
• successful programmes protect entire communities and populations
• to produce high affinity IgG for more effective and efficient immune responses

Question 3

describe the evolution of immunisation programmes

Answer 3

1. disease is prevalent
2. vaccine coverage increases and disease incidence decreases
3. adverse events occur and gain coverage so vaccination uptake decreases and a disease outbreak begins to occur
4. after the outbreak, vaccine coverage increases again and disease incidence decreases until it is eradicated
5. disease has been eradicaed so the vaccine is no longer given and adverse events drop in incidence

Question 4

how do vaccines work?

Answer 4

vaccines expose the immune system to disease causing microbial agens without causing disease by stimulating adaptive immunity and generate long-term immunological memory

Question 5

describe what happens to innate and adaptive immunity when a vaccine is given

Answer 5

1. the epithelial barrier is broken and microbes enter
2. the first cells to respond are the innate immunity cells - phagocytes, dentritic cells, NK cells - which phagocytose and induce inflammatory mediators to recruit more cells
3. dentritic cells present antigens to Tcells (adaptive immunity)
4. T cells become activated and proliferate - now effector T cells
5. some T cells help at the site of infection and some communicate with and activate B cells which produce low affinity IgM antibodies initially
6. activated B cells proliferate and differentiate into plasma cells which produce high affinity IgG antibodies (via affinity maturation - become more specific and have higher affinity)

Question 6

what happens in the primary response?

Answer 6

• low affinity IgM antibodies are produced by B cells
• slower response
• less effective

Question 7

what happens in the secondary response?

Answer 7

• high affinity IgG antibdies are produced by plasma cells
• quicker response
• more effective

Question 8

what are the different types of vaccines?

4

Answer 8

• live attenuated
• inactivated
• subunit (purified antigens) (recombinant, toxoid, polysaccharide, conjugate)
• viral vector

Question 9

what is a live attenuated vaccine?

Answer 9

• live but weakened via genetic modifications
• capable of repilication within host cells
• excellent life-long immunity
• potentially pathogenic in immunocompromised
• one dose required to produce high affinity IgG antibodies

Question 10

what is an inactivated vaccine?

Answer 10

• killed through chemical or physical processes
• cannot replicate and cause disease
• weak immunity
• several doses required to achieve high affinity IgG antibodies

Question 11

what is a subunit (purified antigens) vaccine? describe what each type of subunit vaccine is

Answer 11

• no live components, only parts of antimicrobials
• recombinant - produced by genetic engineering
• toxoid - inactivated bacterial toxins
• polysaccharide - encapsulated bacteria - Tcell independent
• conjugate - polysaccharide antigens linked to proteins
• several doses required to achieve high affinity IgG antibodies

Question 12

what is a viral vector vaccine?

Answer 12

• use of an unrelated harmless virus modified to deliver genetic material (viral vector)
• our cells use the genetic material to make a specific protein
• the protein is recognised by the immune system to trigger a response
• strong and effective response is produced
• need to be stored at specific low temperatures

Question 13

what are adjuvants?

Answer 13

• aluminium/calcium salts
• enhance immune responses to vaccine antigens
• used with inactivated/subunit vaccines
• maintain and prolong antigen stability by activating TLRs
• enchance and prolong antigen presentation
• can cause a granuloma formation under skin
• only used with IM delivery

Question 14

what are the routes of administration of vaccines?

5

Answer 14

• intramuscular
• subcutaneous
• intradermal
• intranasal
• oral