Immunisation

Question 1

What are the types of Passive Ig immunisation?

Answer 1

Pooled - Polyvalent IgG extracted from blood plasma of a multitude of donors. Abs are tested by seeing how it reacts to certain disease associated antigens

Hyperimmune - Prepared from plasma of people with high titres of Ab against organism/Ag. From people recovering from infections or artificially immunised donors

Question 2

What is the cons of passive Ig immunisation

Answer 2

Short lived and potentially hazardous

Question 3

What are the indications for Passive Ig Immunisation?

Answer 3

Question 4

What is meant by active immunisation?

Answer 4

When you need to generate the immune response yourself. Involves introduction of immunising agent.

Question 5

What is meant by unattenuated vax? and give some examples

Answer 5

Different host or route

Respiratory adenovirus - Administered by different route

Rotavirus - Monkey and bovine rotavirus given (from different host)

Question 6

What is meant by empirically attenuated vac? give some examples

Answer 6

Grow MO in conditions it doesn’t grow very well –> resulting in evolutionary progeny with variants which won’t grow well in humans. New species adapted to the new conditions won’t be virulent.

Attaining empirical vax license is extremely difficult. we want rationally attenuated now

Viruses - Sabin OPV, MMR, VZV, rotavirus, yellow fever

Bacteria - BCG, typhoid

Question 7

What is rationally attenuated vaccine?

Answer 7

Cholera - Oral live attenuated vaccine - CVD 103 HgR - made by recombinant techniques –> Doesn’t contain the enzymatic subunit of CT and also has mercury identification gene (HgR)

Question 8

What are resassortants vaccine?

Answer 8

Rotavirus (dsRNA) and Flu (ssRNA) have segmented genome.

Reassort the genome into weak viruses so that we get antigen exposure without deleterious Fx

Rotavirus - RotaTeq

Influenza - Not used in Aus

Question 9

What are vaccine made using Antigen expressed on living vector?

Answer 9

Oral typhoid vac is empirically attenuated - clone genes from other bugs into it (ETEC adhesion Ag) to get a combined typhoid and traveller’s diarrhoea vax

Question 10

What are the advantages of live vax?

Answer 10

• Broader immune response
• Local immunity (sometimes)
• Ease of administration (sometimes)

Question 11

What are non-replicating immunising agents?

Answer 11

Inactivted virion, bacterium

Virus - Polio Salk IPV, influenza, Hep A, Japanese Encephalitis, Rabies

Bacteria - Cholera, typhoid, pertussis, Q fever

Acellular pertussis - 3 or 5 components

Toxoids - Diptheria, tetanus - DPT vax

Capsular PS unmodified 23vPPPV, Vi or conjugated - HiB, 10v PCV

Purified product, component (+/- modification)

Viruses

Hep B - HBsAgs

HPV - VLP (6, 11, 16, 18)

Product of cloned genes

Synthetic immunogen and DNA vax

Inactivated vaccines

Non-replicating immunising agents

Question 12

What are the advantages of killed vax?

Answer 12

• Stable
• unlikely contamination
• can’t spread
• safe for immune deficient individuals

Question 13

What are the disadvantages of killed vax?

Answer 13

Weaker immune response

high dose

need adjuvants

expensive