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29 Cards in this Set
- Front
- Back
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Define immunisation |
making someone immune to a particular disease |
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What is a vaccination |
the deliberate induction of an adaptive immune response by injecting a vaccine (dead or attenuated) for of the pathogen |
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Describe natural immunity |
Immune response towards an infection |
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Describe artificial active immunity |
Attenuated (live) vaccine that has had the disease causing element removed. |
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Describe natural passive immunity |
Neonatal protection. Naturally acquired IgG and IgA from the mother through the placenta to the foetus and milk |
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What is the IgG trough |
The window when the maternal immunisation declines and the child's own immunity is not yet fast enough. The 3-6 month period in which the IgG antibody is declining after birth, and the child's B cells are beginning to produce their own IgG. |
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What is the type of immunity is used for hypogammaglobulenia |
Artificial passive immunity |
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What is artificial passive immunity? |
human or animal IgG that have overcome the infection. |
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Which antibody is most abundant in the absence of an infection? |
IgG |
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Which antibody is most abundant in the initial presence of an infection? |
IgM |
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Which receptors do naive t cells express? |
Protein tyrosine phosphate CD45RA |
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Which receptors do central and effector t cells express? |
CD45RO |
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What is the role of effector memory t cells? |
They rapidly mature into effector t calls upon Ag re-stimulation and lose CCR7 expression, then move into tissues. They release cytokines IFN-gamma and IL-4. |
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What is the role of central effector t cells? |
They mature into effector t cells slower and stay in the LN for longer due to the maintenance of CCR7. They take longer to secrete effector associated cytokines than memory effector t cells. |
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What cytokines do CD8 and CD4 t cells produce? |
IFN-gamma IL-4 Some CD8 express CD45RA |
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What are the 6 features that a vaccine must have to induce memory cells? |
1. Be captured and processed by APC for MHC presentation to activate TCR 2. Activate APC to secrete cytokines 3. Induce high levels of T and B cell primary activation to allow a memory response 4. Activate multiple T cell clones to counter any antigenic variation 5. Provide a constant and long lasting source of antigen in the LN. 6. Induce a protective response to pathogen without causing disease |
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What are the types of immunisation vaccines? |
- Live - MMR, BCG (TB), yellow fever - Attenuated - oral polio - Killed vaccine - pertussis (whooping cough), typhoid, cholera - Conjugate - Recombinant |
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Give an example of a recombinant vaccine? |
HepB |
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What are purified subunit vaccines? |
Made from purified components of pathogens. The components elicit a protective immune response. |
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Give an example of a purified subunit vaccine? |
Haemophilus influenzae B (HiB) which causes meningitis and pneumonia |
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What is the HiB vaccine made from? |
purified capsular polysaccharides, haemagglutinin (H) and neuraminidase (N) antigens of a particular strain. |
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How are conjugate antibodies created? |
covalently attaching poor antigen to a strong antigen, eliciting a stronger immunological response to the poor antigen. |
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What 4 functions to adjuvants have? |
- Extend the presence of an antigen in the blood - Help the APC absorb antigen - Activate macrophages and lymphocytes - Support the production of cytokines |
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Give an example of an adjuvant that has questionable action? |
Alum functions as delivery systems by generating depots that trap antigens at the site of injection, providing slow release that continues to stimulate the immune system. However studies show removal of these depots had no impact on the magnitude of the IgG1 response. |
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Give an example of a newly developed antigen? |
Monophosphoryl lipid A (MPLA) activates TLR4 and is used in HPV vaccines. (human papilloma virus) skin and mucous membranes |
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Describe herd immunity |
The disease incidence declines in a population if the majority are immunised. The estimated threshold of population immunisation is 75-86% for mumps, 85% for smallpox, so requires continuous immunisation to avoid a pool of susceptible hosts. |
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Give 2 examples of vaccines that have had complications in immunity? |
MMR - bad publicity linking it to bowel cancer; 1998, decreased uptake so consequential break outs. Whooping cough - immunisation fell to 30% in 1978 and there were ~30,000 cases of whooping cough which rose to >100,000. -> brain damage. |
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Describe TB and the vaccine? |
Mycobacterium tuberculosis 10.4 million new cases in 2015 1.8 million died (WHO) Bacille Calmetter Guerin (BCG) vaccine contains a live attenuated strain of Mycobacterium bovis. The vaccine prevents TB meningitis in children not very effective in adults, they have respiratory form which it is less specific towards *prog changed that is is now only given to high risk subset |
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What are the requirements of an effective vaccine? |
1. safe 2. high level of protection 3. long-lasting protection 4. right type of response - local - systemic - B or T cells / or both |
