Immunisation Flashcards
When may eradictaed diseases reappear?
When vacciination stops
What is a possible consequence of stopping vaccinations?
Eradicated diseases may reappear
Describe the applications of immunisation?
Prevent infection
Treat infection
Prevent or treat non-infectious conditions (eg. cancer)
Modify immune responses
Modify physiological processes
What are the two broad types of immunisation?
Active
Passive
Describe the two types of passive immunisation?
Which is more common?
Antibodies (more common)
Immune cells
Describe the applications of passive immunisation with Ig?
Treat and prevent infection
Describe the sources of Ig for passive immunisation?
Human
Horse
Monoclonal (modified mouse)
Describe the two types of passive immunisation with Ig?
Standard (pooled): derived from plasma (leftover from blood donors)
Hyperimmune: from people that have very high titres of Abs to common infections
Describe the features of passive immunisation with Ig?
Short-lived
Potentially hazardous (can get immune reactions)
List the living immunising agents for active immunisation?
Unattenuated
Empirically attenuated
Rationally unattenuated
Reassortants
Antigen expressed on living vector
Describe empirically attenuated immunising agents?
Give an example?
Grow agent under conditions that it doesn’t like > eventually adapts > won’t be able to grow in humans anymore
e.g. BCG vaccine
Describe rationally attenuated immunising agents?
Give an example?
Delete genes/components from agent
None licensed at the moment
Used to have live oral cholera vaccine
Describe how immunising agents can have antigen expressed on a living vector?
Give an example?
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
List the living unattenuated vaccines?
Why don’t they cause disease?
Respiratory adenovirus (different route)
Rotavirus (different host - attenuated from other animals)
Vaccinia
List the living empirically attenuated vaccines for viruses and bacteria?
Viruses: polio (Sabin OPV), MMR, VZV, rotavirus, yellow fever
Bacteria: BCG, typhoid (Ty21a)
List the living rationally attenuated vaccines?
Cholera
List the reassortant vaccines?
Rotavirus (RotaTeq)
Influenza (Not in AUS)
List the non-replicating immunising agents?
Inactivated virion, bacterium
Purified product or component
Product of cloned gene
Synthetic immunogen (experimental only)
DNA vaccine (experimental only)
List the inactivated vaccines for viruses and bacteria?
Viruses: polio (Salk IPV), influenza, Hep A, Japanese encephalitis, rabies
Bacteria: cholera, typhoid, pertussis, Q fever
List the component vaccines for viruses?
Hep B (use recombinant DNA)
HPV (use virus-like particles)
List the componnt vaccines for bacteria?
Acellular pertussis
Toxoids: diptheria, tetanus, (cholera)
Capsular polysaccharide: unmodified (23vPPV, Vi) and modified (Hib, 10vPCV, 13vPCV, MenCCV, 4vMenCV)
Which people receive conjugated capsular polysaccahride vaccines?
Children
Describe the advantages of living vaccines?
Broader, more natural immune response
Local immunity (sometimes)
Ease of administration (sometimes - not in remote areas - need cold chain to keep bug alive)
Describe the disadvantages of living vaccines?
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)
