Vaccinations Flashcards
1
Q
Define vaccination
A
- preparation of antigenic material used to induce immunity against pathogenic organisms
- dead/attenuated form of pathogen
2
Q
Define passive immunity
A
- immunisation
- conferred by the transfer of preformed antibodies rather than by active production of antibodies after exposure to antigen
3
Q
Define active immunity
A
- achieved that is induced by natural exposure to a pathogen or by vaccination
4
Q
What are the 4 kinds of immunity and how are they acquired ?
A
- natural active = natural infection
- artificial active = vaccination
- natural passive = transfer of antibody from mother to infant
- natural active = passive antibody therapy
5
Q
What are some uses of passive immunisation ?
A
- prevent infection in ‘ at risk’ individuals
- prevent infection post-exposure
- treatment of infection
6
Q
What are the different kinds of vaccine ?
A
- live attenuated
- inactive/killed
- subunit
- recominbant/DNA
- mRNA
- Toxoids
7
Q
Describe live vaccines
A
- Vaccinia originally used to protect against smallpox
- attenuated, non-pathogenic organism
8
Q
What are some of the problems with live vaccines
A
- induction of anti-viral state
- ineffective when given with antibody
- reversion to virulence
- contraindicated in immunosuppression
- potential for secondary spread
9
Q
Describe inactivated vaccines
A
- inactivation is achieved via heat, phenol or formalin
- poor immuogens due to altered immunogenicity - alum used as adjuvant
10
Q
What is Alum ?
A
- double salt of aluminium, or potassium aluminium sulfate
11
Q
What is adjuvant ?
A
- a substance inducing immune response which enhances the body’s response to an antigen/immunogen administered
12
Q
Describe Subunit vaccines
A
- induce immunity against surface proteins or those involved in invasion
- example = surface antigens - typhoid
13
Q
What are some drawbacks of subunit vaccinations ?
A
- many are poor immunogens which require adjuvants
- ,multiple serotypes of many infections = not protective against all
-predominantly antibody response which is less effective against intracellular organisms
14
Q
Describe Recombinant/DNA vaccines
A
- traditionally more difficult to produce
- examples = Hep B vaccine & rabies vaccine for wildlife
15
Q
Describe mRNA vaccines
A
- delivered into hot cells via lipid nanoparticles
- mRNA translated in the human cell into spike protein
- host cell expresses viral spike proteins on the surface
