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Flashcards in Principles of Immunisation Deck (35)
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1
Q

What are 2 examples of natural passive immunity?

A
  • placental transfer of IgG

- colostral transfer of IgA

2
Q

What are 2 examples of artificial passive immunity?

A
  • treatment with immunoglobulin

- immune cells

3
Q

What is human normal immunoglobulin?

A

contains all antibodies- protein extracted from pooled blood donations

4
Q

What is human specific immunoglobulin?

A

selected blood donor with high antibody titres against a specific organism

5
Q

When is HNIG used for post-exposure prophylaxis?

A
  • hep A
  • measles
  • polio
  • rubella
6
Q

When are specific immunoglobulins used for post-exposure prophylaxis?

A
  • hep B
  • rabies
  • tetanus
  • Varicella-Zoster virus
7
Q

What is an advantage of passive immunity?

A

gives immediate protection

8
Q

What are the disadvantages of passive immunity?

A
  • short term: no immunological memory
  • serum sickness
  • graft versus host disease
9
Q

What is an example of natural active immunity?

A

exposure/infection

10
Q

What is an example of artificial active immunity?

A

vaccination

11
Q

What are the advantages of active immunisation?

A
  • antigen stimulated immune response
  • long term immunity
  • immunological memory
  • faster and better response on second encounter
12
Q

Vaccination

A

the administration of antigenic material to stimulate and individual’s immune system to develop adaptive immunity to a pathogen

13
Q

Why might someone not receive a vaccination?

A
  • febrile illness
  • pregnant woman cannot receive live attenuated vaccines
  • allergy
  • immunocompromised cannot be given live attenuated viruses
14
Q

How does an immune response occur?

A
  • disease causing organism contains antigens
  • antigens stimulate the production of antibodies
  • antibodies bind to the organism and lead to its destruction and memory B cells are formed
15
Q

How are live attenuated vaccines made?

A

attenuation of a pathogenic organism by repeated passage in cell culture or a non-human host

16
Q

Advantage of live attenuated vaccines

A

they elicit strong cellular and antibody responses and often confer lifelong immunity with only one or two doses

17
Q

Disadvantages of live attenuated vaccines

A
  • remote possibility exists that an attenuated microbe could revert to a virulent form and cause disease
  • require refrigeration
18
Q

How are inactivated vaccines produced?

A

by killing the disease causing microbe with chemicals, heat or radiation

19
Q

Advantages of inactivated vaccines

A
  • more stable and safer than live vaccines

- do not require refrigeration

20
Q

Disadvantages of inactivated vaccines

A

stimulate a weaker immune system response than liv vaccines

  • may require and adjuvant
  • boosters likely required
21
Q

What are 4 examples of inactivated vaccines?

A
  • bubonic plague
  • typhoid
  • hep A
  • rabies
22
Q

What are acellular vaccines?

A

use only the antigenic part of the disease causing organism

23
Q

What are the characteristics of acellular vaccines?

A
  • don’t induce the strongest immune response
  • may require boosters
  • cannot cause disease
24
Q

When are toxoid vaccine used?

A

when a bacterial toxin is the main cause of illness- when bacteria secrete toxins or harmful chemicals

25
Q

How are toxins inactivated?

A

treating them with formalin

26
Q

What is an example of a toxoid vaccine?

A

DTaP (diphtheria, tetanus and pertussis)

27
Q

What is a BCG?

A

a vaccine against Mycobacterium bovis to protect against Mycobacterium tuberculosis

28
Q

What is a subunit vaccine?

A
  • a vaccine that only includes the antigens that best stimulate the immune system
  • in some cases they use epitopes- parts of the Ag that Ab or T cells recognise
29
Q

What is a conjugate vaccine?

A

A vaccine which links antigens or toxoids from the microbe that an infant’s immune system can recognise to polysaccharides

30
Q

What problem do conjugate vaccines solve?

A
  • many harmful bacteria have an outer coating of polysaccharides
  • -polysaccharide coatings disguise bacterial antigens so that the immature immune system of infants and children can’t recognise or respond to them
31
Q

What do conjugate vaccines defend against?

A
  • hepB
  • hib
  • pertussis
  • HPV
32
Q

How do DNA vaccines work?

A
  • use only genetic material
  • when the genes for a microbe’s antigens are introduced into the body, some cells will take up that DNA and some cells make the antigen molecules.
  • the cells secret the antigens and display them on their surfaces
  • this evokes a strong antibody response to the free-floating antigen secreted by cells
  • stimulates a strong cellular response against the microbial antigens displayed on cell surfaces
33
Q

Adjuvant

A

a substance which enhances the body’s immune response to an antigen

34
Q

What is the primary aim of vaccination?

A

to protect the individual who receives the vaccine

35
Q

How does herd immunity occur?

A
  • Vaccinated individuals are less likely to be a source of infection to others
  • this reduces the risk of unvaccinated individuals being exposed to infection
  • therefore individuals who cannot be vaccinated will still benefit from routine vaccination programmes