Lecture 3 - Immunisation and immunotherapy Flashcards
Briefly describe how active immunisation works
administering antigen induces antibody and/or T cell response specific to the given antigen. Both systemic and mucosal immunity can be induced. protection not immediate
Briefly describe how passive immunisation works
administer pre formed antibody in order to protect from disease. immediate protection but no immunological memory or immune response generated
Which immunoglobulins are generated at each stage of antibody responce
primary is IgM and secondary is mainly igG
Describe a live attenuated vaccination
one dose of organism who’s virulance has been reduced - organism multiplys in host and immune response same as that of natural infection.
systemic and mucosal
Describe the risks of a live attenuated vaccine
- severe infection in immunocompromised
- organism can revert to normal virulence
- storage conditions are critical
3 examples of a live attenuated vaccine
MMR, BCG, oral polio
Describe a killed vaccination
several doses of inactivated organism - immune response generated. only systemic reaction
stable to store. have to administer with adjunctive which boost immune system
Give and example of an adjunctive used in vaccination
aluminium hydroxide - NOT antigens
Name the risks of a killed vaccination
- risk of reaction
- the inactivated form may change the structure of the organism
Give 3 examples of killed vaccination
killed polio, influenza, pertussis
Describe a subunit vaccination
parts of an organism are administered in several doses with adjuvant. usually only a systemic response. body doesn’t mimmic natural response but does induce response to prevent disease
Give 4 examples of a subunit vaccination
Gr C menningococcal, tettanus, Hep B, hib
Describe subunit conjugate vaccinations
two subunits are bound in order to activate both B cells and T cells. B cells cannot divide unless activated by T cells. e.g. diptheria protein and mennincococcal Gr C polysacharide
Describe some contraindications for vaccines
- acute illness or allergy to previous doses
- live vaccines shouldn’t be used in pregnancy or in immunocompromised (primary e.g. HIV or secondary e.g. steroids chemo)
- allergy to stuff in vaccine e.g. influenza vaccine made with extracts of egg
When should live vaccine doses be given and why
at the same time or several weeks apart (too close together and immune system is suppressed and wont respond to second dose)
Which vaccine cant you give if the patient is on antibiotic therapy
typhoid
Which vaccine is given to splenectomy patients and why?
pneumovax against pneumococcus. no spleen increases susceptibility
What is Human immunoglobulin replacement therapy ?
IgGs derived from plasma of 1000 doners. must be 90% intact. must be biologically active and must no have any inflammatory mediators or infectious agents.
What is in commercial IVIG
lots of antibodies from lots of bacteria/virus’
still active to neutralise toxins and activate compliment
When would commercial IVIG be given?
Primary immunodeficiencies:
-B cells e.g. x linked agammaglobulinaemia or hyper igM
-T cell deficiency (as activates)
Secondary immunodeficiencies:
- chronic lymphocytic leukaemia or multiple myeloma
- HIV in children with recurrent infections
- premature babies with recurrent infections
- early onset neonatal sepsis
How are specific immunoglobulin preparations produced in replacement Ig therapy
either plasma pre screened for high titres of antibody
or volunteers vaccinated first so prod loads of ABs e.g. rabies
Give examples of hyperimmune immunoglobulin for post exposure treatment / prophylaxis
rabies (bitten), RSV, Hepatitis (e.g. needle stick injury), tetanus, VZV( if mother develops chicken pox within 5 days of birth, CMV if immunosuppressed
What are monoclonal antibodies?
Artificially produced antibodies of a single specificity derived from a single B cell clone.
Name three positives to using monoclonal antibodies
endless supply
highly specific and more potent than immune sera
reduce risk of transferring infection
Name 4 biological activites of cytokines
stimulation of cells in immune system
stimulation of inflammation
stimulation of haematopoiesis
anti-viral and anti-proliferative activities
Describe two occasions when interferon alpha therapy is appropriate
Hepatitis B - 50% response rate though
Hepatitis C in combination with Ribavirin (or pegintereforon alpha)
How does interferon alpha cytokine therapy reduce viral activity
inhibiting viral replication and protein synthesis
stimulating antiviral immune responce
How are circulating neutrophil levels enhanced in cytokine therapy ? Why is this a benefit and in what?
1) granulocytes CSF and granulocytes and macrophages CSF
2) -reduces febrile neutropenia in cytotoxic chemo
- reduces duration of neutropenia in myeloblative therapy followed by BMT
Why is interferon gama used in cytokine therapy? example of when this is used and how it works?
enhances phagocyte function e.g. in chronic granulomatous disease
- CGD phagocyte NADPH oxidase gene defect therefor reactive oxygen metabolites not generated (needed for killing bac). interferon gama upregs NADPH oxidase
