1
Q
What is passive immunity?
A
- Antibodies are passed onto but not made by the body
- body does not have template to make the antibody
- cannot make antibody again if needed
- once circulating antibodies disappear, no more immunity will be conferred
2
Q
What is active immunity?
A
- antibodies are made by the body
- body has the template to make antibody (memory)
- can make new antibodies if needed
- protected for life
3
Q
What is naturally acquired immunity
A
- come into contact with pathogen normally
- naturally acquired passive immunity, e.g. breast milk antibodies
- naturally acquired active immunity, e.g. catching chicken pox and being immune for life
4
Q
What is artifically acquired immunity?
A
- needs outside intervention
- artificially aquired passive immunity, e.g. injection with antibodies
- artificially acquired active immunity, e.g. vaccines
5
Q
What is immunisation?
A
- the process of making a person or animal immune to infections, typically by inoculation
- safe and effective way of protecting susceptible hosts
6
Q
How does immunisation work?
A
- deliver something resembling infectious agent (but not harmful) into the body
- trick the body into activating 3rd line defence
- t-lymphocytes (cell mediated)
- b-lymphocytes; make IgM first followed by memory antibody IgG
- therefore when the real pathogen enters the body, IgG will recognise and neutralise it before the person becomes sick
7
Q
What is herd immunity?
A
- if the majority of the population is vaccinated, then the disease will not spread easily; indirect protection
- those that are not immunised will benefit from herd immunity
- ~85% immunisation = coverage, but depends on disease
- protecting too young, those with immunosuppression, allergies, etc
8
Q
What must a vaccine be in order to be effective?
A
- protective
- safe
- lasts
- practical
9
Q
What is live attenuated vaccine?
A
- weakened live MO
- can grow but not cause damage
- response virtually identical to natural infection
- usually just need one dose, unless oral
- both antibody and T cell involved - strong immunity
- e.g. measles, mumps, rubella, varicella, oral polio
- potential problems; may revert to ‘wild type’ - wake up from coma
10
Q
What is an inactivated vaccine?
A
- whole MO, dead (or very badly injured)
- some may use the ‘business’ part of the MO
- require multiple doses
- first ‘primes’ immune system
- next = develop protective response
- mistly antibody, so wanes over time
11
Q
What is a pollysaccharide vaccine?
A
- ‘inactivated subunit’
- ID markers of the bug (antigens)
- work better if conjugated; a poor antigen is attached to a strong antigen, elicits a T-cell response
- e.g. HiB, meningococcal disease
12
Q
What is a recombient vaccine?
A
- genetically engineered
- grow just the ‘ID marker’ that is recognised
- e.g HBV, HPV
