Immunology 1: Vaccination Flashcards
What is a vaccination?
Developing immunity against a particular pathogen, either naturally or via vaccine.
What is immunological memory?
The ability of the immune system to recognise a previous pathogen that affected the body and produce a more efficient response.
Which 4 cell types of the immune system show immunological memory?
- Memory CD4+ T cells 2. Memory Cytotoxic T cells 3. Memory B cells 4. Long lived plasma cells
Which two Ig types are primarily involved in the immune response?
- IgG 2. IgM
What is the difference in the pattern of Ig production in primary vs secondary response?
Primary- IgM first, takes two weeks for IgG to be produced and be the most prominent IG.
Secondary- IgG and IgM both produced at the start, IgG at the higher concentrations
How is the memory based immune response different to primary infection?
Response generated is much quicker, and a lot stronger (greater number of specific effector cells produced)
Vaccination can also generate memory T & B cells. T/F?
True
Second and subsequent exposure to a pathogen is more rapid and aggressive. T/F?
True
What five factors makes the secondary immune response faster?
- Memory cells present in greater numbers
- Memory CD8+ cells can immediately kill pathogens
- Memory CD4+ cells can immediately produce cytokines
- Memory B cells have already undergone hypermutation and can immediately produce high conc of IgG and other high affinity antibodies
- Memory cells have enhanced properties of cell adhesion and chemotaxis.
What is the difference between active and passive immunity?
- Active- Immunity generated by the person themselves. Can be via vaccine or natural 2. Passive- Immunity gained from other person/animal
Active immunity tends to be permanent while passive usually temporary. T/F?
True
What are the 4 different ways of inducing immunological memory?
Exposure to
- Infectious organism
- A similar but less virulent pathogen
- An inactivated form of the pathogen
- A less virulent but the same pathogen.
What is variolation?
Exposure of people to small pox derived from other individuals
Exposing someone to coxpox to prevent immunity from small pox is an example of?
Active immunity- exposure to similar but less virulent pathogen
Exposing someone to an inactivated form of the pathogen is more effective than using an active form. T/F?
False. The response is mediated primarily by antibodies, not T cells Needs multiple doses to stimulate effect
What are the two main symptoms of polio?
- Muscle weakness 2. Paralysis
People who have polio are usually asymptomatic. T/F?
True
What are the pros of inactivated vaccines? (2)
- Can be made quickly - Can be given to immunocompromised
Disadvantages of inactivated vaccines? (3)
- May be difficult to stimulate immune response to killed organism
- No T cell production
- Requires repetitive exposure to generate response
What are adjuvants?
Inflammatory substances administered with the vaccine to boost the chances of an immune response
Pros and cons of adjuvants? (1 each)
Pro -inflammatory substances stimulate antibody & T cell production
Cons- Response may be generated to vaccine:protein conjugate rather than to the vaccine itself
Difference between whole cell and subunit vaccines?
Whole cell- all of pathogenic organism used (Hep A) Subunit- only part of the organism used (Hep B) Polysaccharide vaccines- sugars from outer capsule of bacteria used to generate immunity to the bacteria
What is a live attenuated virus?
Using a weakened form of the pathogen (Eg measles, mumps, BCG)
Main advantage and disadvantage of attenuated virus?
Adv- V similar to natural infection, so produces near similar immune response (similar T & antibodies) Disadv- Can cause infection in immunocompromised host
What is a natural form of passive immunity?
Maternal antibody transfer to growing foetus. Provides immunity at the time and imp for memory of immunity too. Can be through breast milk or trans-placental transfer of IgG
What is the other form of passive immunity ?
Therapeutic passive immunisation- Taken from unrelated individuals - pooled normal human immunoglobin - hyper immunoglobin Pooled - Taken from a bank of people who have immunity to the virus Hyper- taken from peeps with high antibody levels against the pathogen
