L03 - Immunisation & Immunotherapy Flashcards
Define Active Immunisation (Vaccination)
Administration of antigen in order to induce active production of immunity
Describe the characteristics of Active Immunisation
Immunity is specific for antigen given Immunological memory is induced Immunity involves antibody/T-cell response Systemic/Mucosal immunity is possible Protection is not immediate
Define Passive Immunisation
Administration of pre-formed antibody in order to protect from disease
Describe the characteristics of Passive Immunisation
No immunological memory is generated
No immune response in the recipient
Protection is immediate
Define the Primary Antibody Response
Shortly after vaccination
Induces formation of memory cells
Mainly IgM
Define the Secondary Antibody Response
After secondary exposure to antigen
Faster, peaks higher
Mainly IgG
Define Live Attenuated Vaccines
Vaccines consisting of organisms whose virulence has been reduced ie. by repeated culture in vitro (MMR)
Not possible for all viruses
Describe the characteristics of LAVs
Multiply in the host, mimic natural infection but with no/mild symptoms
Systemic/mucosal immunity forms with long lasting immune memory
Usually only one dose is needed
Describe the risks of LAVs
Potential for severe infection (immunodeficiency)
Potential to revert to virulent strain
Storage conditions critical for stability
Define Killed Viruses - Give an example
Vaccines consisting of whole inactivated virus/bacteria (Polio)
Not suitable for all organisms
Describe the characteristics of KVs
Do not multiply in the host
Only systemic immunity induced
Several doses needed (large amount of antigen req.)
Describe the risks of KVs
Inactivation may alter structure
No risk of infection/reversion
More stable
Define Subunit Vaccines - Give an example
Vaccines consisting of parts/products of organisms (Group C Meningococcus)
Describe the characteristics of SVs
Immunisation does not mimic natural infection BUT induces a response to prevent disease
Only systemic immunity induced
Several doses needed (inc. adjuvant)
Describe the risks of SVs
No risk of infection/reversion
No unwanted components
Give three examples of contraindications to immunisation common to all vaccines
Acute illness
Severe reaction to previous dose of same vaccine
Patient known to be allergic to vaccine/component
Give three examples of contraindications to immunisation specific to LVs
Pregnancy
Primary or Secondary Immunodeficiency
Give three examples of situations where vaccines may not work
LV given to patients on antibiotics
Patients on immunoglobulin therapy
LVs given close together (give at the same time or weeks apart)
Define Immunoglobulin Replacement Therapy
A type of passive immunisation where immunoglobulin is given (i.v. or s.c.)
How are IVIG preparations produced?
Derived from pooled plasma of >1000 donors IgG must be >90% intact with a range of subclasses Biologically active (activates complement, binds FcR) Free of inflammatory mediators/infectious agents
What are the indications for the use of IVIG?
Primary antibody deficiencies
Secondary antibody deficiencies
Describe Hyperimmune/Specific Immunoglobulin Preparations
Selected for v. high titres of antibodies to spec. microbes
Used for post-exposure treatment/prophyalxis
Define monoclonal antibodies
Artificially produced antibodies of a single specificity derived from a single B cell clone
Describe the characteristics of MABs
Endless supply
Fully homogenous & characterised reagent (highly specific/potent)
Reduced risk of transferring infection
