Immunisation

Question 1

When may eradictaed diseases reappear?

Answer 1

When vacciination stops

Question 2

What is a possible consequence of stopping vaccinations?

Answer 2

Eradicated diseases may reappear

Question 3

Describe the applications of immunisation?

Answer 3

Prevent infection

Treat infection

Prevent or treat non-infectious conditions (eg. cancer)

Modify immune responses

Modify physiological processes

Question 4

What are the two broad types of immunisation?

Answer 4

Active

Passive

Question 5

Describe the two types of passive immunisation?

Which is more common?

Answer 5

Antibodies (more common)

Immune cells

Question 6

Describe the applications of passive immunisation with Ig?

Answer 6

Treat and prevent infection

Question 7

Describe the sources of Ig for passive immunisation?

Answer 7

Human

Horse

Monoclonal (modified mouse)

Question 8

Describe the two types of passive immunisation with Ig?

Answer 8

Standard (pooled): derived from plasma (leftover from blood donors)

Hyperimmune: from people that have very high titres of Abs to common infections

Question 9

Describe the features of passive immunisation with Ig?

Answer 9

Short-lived

Potentially hazardous (can get immune reactions)

Question 10

List the living immunising agents for active immunisation?

Answer 10

Unattenuated

Empirically attenuated

Rationally unattenuated

Reassortants

Antigen expressed on living vector

Question 11

Describe empirically attenuated immunising agents?

Give an example?

Answer 11

Grow agent under conditions that it doesn’t like > eventually adapts > won’t be able to grow in humans anymore

e.g. BCG vaccine

Question 12

Describe rationally attenuated immunising agents?

Give an example?

Answer 12

Delete genes/components from agent

None licensed at the moment
Used to have live oral cholera vaccine

Question 13

Describe how immunising agents can have antigen expressed on a living vector?

Give an example?

Answer 13

Take an exisiting living vaccine > clone genes into it for virulence factors of other bugs (e.g. clone genes for e.coli adhesins into attenuated live salmonella typhi > combined travellers diarrhoea vaccine)

No examples yet

Question 14

List the living unattenuated vaccines?

Why don’t they cause disease?

Answer 14

Respiratory adenovirus (different route)

Rotavirus (different host - attenuated from other animals)

Vaccinia

Question 15

List the living empirically attenuated vaccines for viruses and bacteria?

Answer 15

Viruses: polio (Sabin OPV), MMR, VZV, rotavirus, yellow fever

Bacteria: BCG, typhoid (Ty21a)

Question 16

List the living rationally attenuated vaccines?

Answer 16

Cholera

Question 17

List the reassortant vaccines?

Answer 17

Rotavirus (RotaTeq)

Influenza (Not in AUS)

Question 18

List the non-replicating immunising agents?

Answer 18

Inactivated virion, bacterium

Purified product or component

Product of cloned gene

Synthetic immunogen (experimental only)

DNA vaccine (experimental only)

Question 19

List the inactivated vaccines for viruses and bacteria?

Answer 19

Viruses: polio (Salk IPV), influenza, Hep A, Japanese encephalitis, rabies

Bacteria: cholera, typhoid, pertussis, Q fever

Question 20

List the component vaccines for viruses?

Answer 20

Hep B (use recombinant DNA)

HPV (use virus-like particles)

Question 21

List the componnt vaccines for bacteria?

Answer 21

Acellular pertussis

Toxoids: diptheria, tetanus, (cholera)

Capsular polysaccharide: unmodified (23vPPV, Vi) and modified (Hib, 10vPCV, 13vPCV, MenCCV, 4vMenCV)

Question 22

Which people receive conjugated capsular polysaccahride vaccines?

Answer 22

Children

Question 23

Describe the advantages of living vaccines?

Answer 23

Broader, more natural immune response

Local immunity (sometimes)

Ease of administration (sometimes - not in remote areas - need cold chain to keep bug alive)

Question 24

Describe the disadvantages of living vaccines?

Answer 24

Disease: back mutation (empirically attenuated can become virulent again), spread (to someone that is not immunised), contamination (another agent may enter, but cannot sterilise)

Failure: dead (need cold chain), pre-existing immunity (passive - from Mum), interference (might prevent immune response if infected with another organism)

Question 25

Describe the advantages of killed vaccines?

Answer 25

Stable

Contamination unlikely

Can’t spread

Safe for immune deficient

Question 26

Describe the disadvantages of killed vaccines?

Answer 26

Weaker immune response

Higher dose

Need adjuvants - more likely to cause some side effects

Expensive

Question 27

Why are vaccinations given at specific times on vaccination schedules?

Answer 27

FIND ANSWER

Hep B at birth - can be exposed at birth

Measles - passive immunity from Mum, so wait until 1 year