Vaccines

Question 1

What are the ideal properties fo a vaccine?

Answer 1

• broadly protective agaisnt all variant of an organism
• prevent disease transmission
• effective immunity rapidly
• effective in all vaccinated subjects
• few immunisations to imnduce protection
• cheap and stable
• Limited side effects

Question 2

B Cell response to a Vaccine?

Answer 2

• Dendritic cell picks up antigen- acivated
• migration ot lymph nodes
• B cell acitvated in lymph node follicle
• differeniatate into short lived plaasma cell
• large scale production of IgM mainly
• long lived plasam cell egenrated in germinal centre of lymph node- requires antigen specific Th cell
• steady porduction of igG- provide life long immunity
• central ememory cells produced in paralle to long lived plasma cells- slowly diivide to maintain populations

Question 3

whats are the differences between the primary and secondary response

Answer 3

• Primary- mainly igM- few days later IgG
• secondary response- very quick - large response production of IgG from the memeory B cells- stronger secondary reponse,

Question 4

How to antibodies prevent infection?

Answer 4

bjnd to active site of toxins/ stop diffusion

neutralsie viral replication

opsonisation

complement activation

Question 5

Describe the T cell response to a Vaccine?

Answer 5

• Dendriict cell picks up antigne
• migration to lymph node and antigen presenation
• T cell acitavted
• differeniate into Effector T cells- CD8+ lymphocyte (kill infected cells)
• or differeniate into CD4+ Th cells - cytokine production, maintenance of B cells and CD8 + cell response
• a small proportion- memory effector celsl.
• central memroy T cells have potential to proliferative ready for reacitvation

Question 6

When is the Cd8 t cell response induced? with regards to type of vaccine

Answer 6

onluy induced when cells are INFECTED- so vaccine would have to be alive- live

Question 7

what is an inactiavted vaccine?

Answer 7

Killed bacteria/virus

Bacterial or viral sub-unit

Peptide or polysaccharide

Toxoid ( inactivated bacterial toxin)

Viral like particle (VLP)

RNA vaccines -COVID

Question 8

what are live vaccines?

Answer 8

Attenuated mostly or a virulent virus- flu vaccine nasal in children

Question 9

Inactivated vs Live Vaccines?

Answer 9

inactivated vaccines- need more doses, require adjuvant (substance used to produce more robust immune response)- shorter term immunity, weak T cell response (not infecting cells)

Question 10

describe Polysaccharided reived vaccines (give and example of one)

Answer 10

Pneumoccoal conjugate Vaccine 13 (PCV13)

less immunogneic, derived form bacterial polysacchairde- rarely induc eT cell response

need to give wvia conjugation protein (storng immunogne) to illict longer term immunity and T-cell mediated immunity

Question 11

What is the rationale behind national vaccination schedulues?

Answer 11

wide range of viruses and bacteria from 8 weeks old to 70 years old and above.

mostly given when young.

• effective vaccine progrmas- save millions of pounds in health care cost-
• herd immunity
• some like small pox very sucessful

Question 12

Negatives to Vaccine development

Answer 12

vaccine development is time consuming and coslty, not always sucessful

less serious diseases and ones that affect fewer people or have more seotypes - no incentive too dificult to get vaccine (common cold)

Question 13

what must a potential disease vaccine candidate have to be viable

Answer 13

cause signifcant illnes

only one serotype

antibody blocks infectio. or systemic spread

infectious agent does not have oncogenic potnetial

heat stable

Question 14

what are the risks of vaccines and are they worth it?

Answer 14

vaccinating is safer than not vaccinating

• common side efects
  
  • injection site recations
  • mild fever
  • shivering
  • fatigue
  • headache
  • muscle and joint pain
• rare
  
  • anaphylaxis