Immunisation

Question 1

What is passive immunisation?

Answer 1

Preformed immunity from person or animal to other person
Adv: immediate protection, effective in immunocompromised
Disadv: short lived ,poss transfer of pathogens, serum sickness

Question 2

Difference between specific and normal immunoglobulins?

Answer 2

Specific - human tetanus Ig, human rabies Ig

Non-specific - prepared pool 1000s donors - ab against MMR, hep A

Question 3

Describe ab response?

Answer 3

APC phagocytose Ag - present to CD4 and T cell via MHCII
Turns into Th2 cell - bind to B cells presenting Ag
Th2 secrete cytotoxin = clonal expansion B cells
Diff plasma cells

Question 4

What are two difference active immunisation?

Answer 4

Non-living and living

Question 5

What are non-living vaccine?

Answer 5

1st exposure - latent period and small ab resposne
2nd exposure - smaller latent period - larger ab response
Example - diptheria and tetanus (pertussis whole killed)

Question 6

What are whole killed?

Answer 6

Grown in vitro and inactivated (formaldehyde)
Don’t cause infection - ag stimulation immune response

Problem
Organism need to be grown to high titre - hard and expensive
Whole pathogen can cause reactogenicity
Immune response not always close to normal

Example: Hep A, influenza, rabies

Question 7

What is a live attenuated vaccine?

Answer 7

Organism that replicates within the host - induce immune response which is protective against wild type organism

Adv: lower dose required, immune response mimic real infection, fewer dose and more favourable route of admin

Disadv: hard balance attenuation and immunogenicity, not so attenuated in immunocompromised pt

Question 8

Give viral and bacterial example of live attenuated vaccine?

Answer 8

BAC: BCG
Viral: MMR

Question 9

Give examples of pathogen lacking vaccines

Answer 9

HIB, malaria, HSV

Question 10

Explain pathogen lacking vaccines?

Answer 10

Pathogens hard to grow
Impossible to obtain attenuated and suitable immunogenic strain
Too many strain cause disease

Question 11

Name 5 novel approaches to vaccination

Answer 11

Recombinant products
Synthetic peptides
Live attenuated vector
DNA vaccine 
T independent antigens

Question 12

How to recombinant products work?

Answer 12

Genetically engineered - bacteria/ yeast
Don’t have to be grown in vitro
e.g HepB surface antigen, HPV

Question 13

How do synthetic peptides work?

Answer 13

Avoid need pathogen growth

inducing strong and broad response in problem

Question 14

How do live attenuated vectors work?

Answer 14

Safe living attenuated virus - genes inserted encode ag
Genetically stable
Potential problem immunodeficient pt

Question 15

How to DNA vaccine work?

Answer 15

Inject expression plasma - express protien
Adv: avoid growth pathogen, no live organism, DNA cheap produce
Disadv: poor immunogenicity

Question 16

What are T independent antigens?

Answer 16

Bacterial capsular polysaccharide that can’t be processed and presented - no T cell help reduced ab response
Polysaccharide not processed but proteins expressed - strong ab response
e.g N. Menigntits and H. Influenza

Question 17

What % of vaccination is needed for herd immunity?

Answer 17

95%