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Basic Immunology- Module 1 > Vaccination > Flashcards

Flashcards in Vaccination Deck (32)
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1

Why has it been so difficult to vaccinate against malaria; TB and HIV?

antibody responses are not sufficient for full protection

2

What is an attenuated organism?

organisms with reduced pathogenesis which stimulate protective immunity but don't cause disease

3

Why do survivors of tetanus required vaccination to be protected against another attack?

the tetanus exotoxin is so powerful that the tiny amount needed for disease can be insufficient for a protective immune response

4

What are the criteria for effective vaccines?

safe; protective; gives sustained protection; induces neutralising antibody; induces protective T cells; practical- low cost; ease of administration; low SE profile

5

Why are inactivated vaccines less potent than live-attenuated vaccines?

inactivated have been treated so that they cannot replicate therefore do not produce proteins in the cytosol of infected cells so peptides are not presented on MHC-I moleules so CD8 T cells are not generated

6

How are attenuated vaccines generated?

pathogenic virus is isolated and grown in human cells then transferred to other animal cells where it then acquired mutations that allow it to grow well in monkey cells, then it no longer grows well in human cells

7

What is the problem with attenuated virus strains?

although they contain multiple mutations in genes, it may be possible for a pathogenic virus strain to reemerge by a furhter series of mutation; also in immunocompromised individuals

8

What method may supersede empirical approaches to attenuated virus generation?

recombinant DNA technology

9

How does recombinant DNA technology in developing attenuated vaccines work?

isolate virus; isolate virulence gene then mutate or delete the gene resulting a viable, immunogeneic but avirulent virus

10

Why is the route of vaccination an important determinant of success?

to induce host defense at the point of entry of the infectious agent- e.g in influenza, IgA antibodies are much more effective at preventing URT infection than systemic antibodies

11

What is the most effective defense against meningococcus; pneumococcus and H.influenzae?

opsonisation of the polysacchradie coat with antibody

12

How does conjugate vaccination work in Hib?

B cell binds polysaccharide epitope linked to tetanus toxin which is then internalised and processed; peptides from hte toxin are presented to the T cell which then stimualtes the B cell to produce antibody against polysaccharide

13

What are the problems with peptide-based vaccines?

a particular peptide may not bind to all the MHC molecules in a population as it is highly polymorphic; some direct exchange of short peptides can occur as processing isn't required e.g if peptides loads onto cells other than DCs this can cause tolerance; need cross presentation by certain types of DC

14

What is an adjuvant?

a compoent which enhacne the immunogenicity of antigens

15

How was DNA vaccination discovered?

DNA encoding a viral immunogen when injected IM inducd antibody responses and cytotoxic T cells that could protect against subsequent infection from the live virus

16

How does DNA vaccination work?

the antigen is produced by cells that are transfected by the DNA e.g skin or muscle

17

How can chronic diseases be differentiated?

ones in which there is an obvious immune response that fails to eliminate the organism and ones where the infectious agent is invisible to the immune system

18

What type of vaccine is diphtheria ?

toxin-based

19

What type of vaccine is Hib?

conjugate polysaccharide

20

What type of vaccine is MMR?

live-attenuated

21

What type of vaccine is BCG?

live-attenuated

22

What type of vaccine is influenza A virus?

killed

23

What type of vaccine is sabin polio?

live-attenuated

24

What phenomenon does a conjugated vaccine exploit?

linked recognition

25

What is the protection of different subtypes of virus by a vaccine called?

heterosubtypic

26

What is a problem with oral immunisation?

may induce oral tolerance as oral route needs to deal with many antigens through the gut

27

What is the immune receptor fro the adjuvant alum?

NLRP3

28

What is the immune receptor fro the adjuvant freunds complete adjuvant?

NOD2

29

What is the immune receptor fro the adjuvant LPS?

TLR4

30

What is the immune receptor fro the adjuvant DNA?

TLR9