CMB2004/L11 Immunisation Flashcards
Give an example of active natural immunity.
Natural infection
Give an example of active artificial immunity.
Immunisation
Give an example of passive natural immunity.
Placental transfer of maternal IgG
Give an example of passive artificial immunity.
Human IgG (normal or immune)
Describe passive immunity.
Short-lived (IgG half-life 3 weeks)
Hypogammaglobulinaemia in infants as maternal IgG declines
IVIgG every 2-4 weeks or immunodeficiency to maintain protective levels
Tetanus antitoxin
Describe active immunity.
Exploits immunological memory
Compare the secondary immune response to primary. (3)
Faster
Greater in magnitude
May be qualitatively better
Who is protected by herd immunity? (2)
Individual
Population
Give 3 requirements of an effective vaccine.
Safe
High level of protection
Long-lasting protection
Right type of response
Low cost
Stable
Easy to administer
Minimal side-effects
Give the 5 types of vaccine.
Inactivated
Attenuated
Subunit
Toxoid
Conjugate
What is an attenuated vaccine?
Live but virulence disabled organisms
E.g., Salk polio vaccine, smallpox, sabin, MMR, BCG
What is a subunit vaccine?
Protein fragments
E.g., Hep B, pneumococcal polysaccharide
What is a toxoid protein?
Bacterial toxin
What is a conjugate vaccine?
Something with low antigenic property covalently bound to something with high
E.g., Hib, MenC, Pneumococcal Prevnar 13
Give 2 pros to live vaccines.
Single dose effective
May be given by natural route
May induce local and systemic immunity
May induce right type of response
Give 2 cons of live vaccines.
Reversion to virulence
Possibility of contamination
Susceptible to inactivation
Causes disease in immunocompromised host
Describe polio.
Enterovirus
Faecal-oral spread
+ve sense RNA
How do conjugate vaccines work?
Convert TI-2 polysaccharide antigen to TD form
What are adjuvants?
Substances administered with an antigen to promote immune response
- by providing a ‘depot’
- Immunostimulatory properties
Give 2 ways in which adjuvants can work.
Activate dendritic cells via TLRs or NLRs
Cause release of endogenous danger signals
Promote antigen uptake by dendritic cells
Stimulate release of chemokines/cytokines
Promote cross-presentation of exogenous antigens by class I
Give 2 animal adjuvants.
Freunds: oil in water emulsion
Freunds complete: also contains mycobacteria
What is used in human adjuvants?
Aluminium hydroxide or aluminium phosphate
What is MF59 adjuvant?
Squalene based oil in water emulsion
Licensed since 1997, used in some flu vaccines
What is AS03 adjuvant?
Includes squalene and vitamin E
Approved 2008 for GSKs H1N1 flu vaccine
What is AS04 adjuvant?
Alum plus monophosphoryl lipid A (LPS derivative)
Approved 2005 for HBV vaccine
