Vaccine Delivery 1 Flashcards
Describe how vaccines work
Vaccines contain antigens
Antigens trigger a primary immune response
T cells and B memory cells are then produced for the specific pathogen
Upon reinfection with the same pathogen a faster secondary immune response is triggered
Is the effect of a vaccine permanent?
Immunity may not be permanent
Booster vaccine may be required
List the characteristics of an ideal vaccine
Stimulate immune response with causing symptoms of disease
Be effective in everyone
Cheap to produce
Easy to manufacture
Be stable
Be available as oral preparation
(However this does not exist, lol , Pharmacy L)
What are the advantages of the Oral Polio Vaccine (Sabin Vaccine)
Easily administered (oral)
Protects against infection of wild type polio
Promotes antibody production in the GI tract
Cheap
What are the disadvantages of the Oral Polio Vaccine (Sabin Vaccine)
Risk of contracting polio from the vaccine
List the components of the innate immune system
Skin - physical barrier + fatty acid secretion
Mucous membranes - Mucociliary Clearance
Blood - phagocytes
Ears - lysozymes hydrolyse pathogen cell wall
Stomach - stomach acid is unsuitable environment
Describe the immune response when a pathogen enters the body (5 main points)
- Bacterial replication causes tissue damage
- Cell damage causes activation of local lymphocytes
- Pathogens are recognised by T cells
- B cells produce antibodies
- Antibodies bind to surface receptors on pathogens
What cells are involved in the humoral response
B cells
Antibodies
What cells are involved in the cell mediated response
T cells
e.g. Helper T cells and Killer T cells
What are immunoglobulins also known as
Antibodies
Describe the structure of an antibody
4 polypeptides
- 2 identical heavy chains
- 2 identical light chains
Held together by disulphide bridges
What are the 5 classes of antibodies
IgG
IgA
IgM
IgE
IgD
What does the variable region of an antibody determine
What antigen the antigen binding site will bind to
How are antibody-antigen complexes removed from the body
Removed by phagocytosis by macrophages
Which class of antibodies is mainly involved in primary response
IgM
Which class of antibodies is mainly involved in secondary response
IgG
(Higher binding affinity to the antigen)
What are the 3 problems with the immune response?
Autoimmunity - body cannot distinguish self and non-self antigens
Immunodeficiency - inadequate immune response
Hypersensitivity - overactive response to certain antigens
What are the 2 types of immunisations?
Active immunisation and Passive immunisation
What is active immunisation?
Stimulation of immune response through deliberate exposure to a pathogen
With the aim of forming immunity to the antigen
What is passive immunisation?
Introducing pre-formed antibodies to a specific pathogen
Does not evoke immune response
List the 5 main vaccine types
Inactivated
Attenuated
Subunit
DNA/RNA
Toxoids
Give an example of each type of vaccine
Inactivated - hepatitis A
Attenuated - MMR
Subunit - Streptococcus Pneumoniae
DNA/RNA - IM injection of DNA/RNA which encodes for viral pathogen
Toxoids - Tetanus
How does an inactivated virus work?
Immune system sense virus but the virus is unable to replicate and spread as it has been ‘killed’
How do subunit vaccines work?
Made of H and/or N proteins only
H and N proteins are able to generate an immune response
How does a DNA vaccine work?
Gene for H protein is isolated
It is injected into human body
Human cells then produce H protein
Generates immune response to H protein
What is the difference between a RNA and DNA vaccine?
RNA is one step ahead
DNA vaccines need to be decoded in the nucleus
RNA vaccines are processed directly in the cytosol
What is the purpose of an adjuvant in a vaccine?
To help provoke an early, long-lasting immune response with less vaccine
What are the benefits of using an adjuvant in a vaccine?
Reduce cost (reduces amount of antigen require)
Reduce need for boosters (provides long lasting response)
What is the mechanism of action of an adjuvant?
Enhance the passage of the antigen to the local node
+
Depot effect - prolong the delivery of the antigen
Name a commonly used adjuvant for a vaccine
Aluminium Salt e.g. AlOH3
What are the issues with aluminium salts as adjuvants?
Cannot be frozen, have to be refrigerated (more expensive)
Can interact with the antigen
Vaccine cannot be used on a mucosal membrane
Do not work with all antigens
