Vaccines 2

Question 1

Three Components of a Vaccine

Answer 1

1. Antigen (target)
2. Adjuvant (primer)
3. Route and Dose

Question 2

What is an antigen?

Answer 2

The specific target seen by the Adaptive immune system

Question 3

What are the 3 main kinds of vaccines?

Answer 3

1. Live attenuated
2. Killed
3. Subunit or Toxoid

Question 4

What is a live attenuated vaccine?

Answer 4

Weakened or less virulent pathogen

Question 5

How does a live attenuated vaccine work?

Answer 5

Weakened pathogen actually infects the host

Attenuated microbes multiply in the recipient, leading to a more robust and long-lasting immune response

Question 6

What type of response does a live attenuated vaccine elicit?

Answer 6

A strong cellular and humoral response

Question 7

How long is immunity for live attenuated vaccines?

Answer 7

Lifelong with only one or two doses

Question 8

What are the 2 risks associated with live attenuated vaccines?

Answer 8

1. Possibility that attenuated vaccine strain could revert to an active pathogen
2. Cannot be given to health professionals or immunocompromised individuals

Question 9

Why can you not give a live attenuated vaccine to a healthcare worker?

Answer 9

Could pass to a patient

Question 10

Why can you not give a live attenuated vaccine to an immunocompromised individual?

Answer 10

It is possible that the weakened pathogen could still win

Question 11

Immunocompromised

Answer 11

Recognizes pathogen as self

Question 12

Autoimmune

Answer 12

Recognizes self as pathogen

Question 13

What are the 2 logistical problems to live attenuated vaccines?

Answer 13

1. need to be refrigerated to stay potent
2. Difficult to produce live attenuated vaccines in bacteria b/c of the greater number of genes and thus, the chance of them reverting is greater

Question 14

Why do we not have attenuated bacterial vaccines?

Answer 14

Bacteria have too many genes and thus, the chance of them reverting is too high

Question 15

What is arguably the safest vaccine?

Answer 15

Killed

Question 16

What is a killed vaccine?

Answer 16

A vaccine containing inactivated organisms or parts of them

Question 17

Give an example of an attenuated vaccine

Answer 17

Measles, mumps

Question 18

Give an example of a killed vaccine

Answer 18

Hep A
Influenza
Polio

Question 19

How do you inactivate - for killed vaccines?

Answer 19

Heat/chemical/radiation

Boil, UV

Question 20

What is an advantage killed has over attenuated?

Answer 20

Pose no risk of reverting

Question 21

How are killed stored?

Answer 21

Dried and stored (up to 10 yrs)

Stable and do not require cold chain

Question 22

What is a drawback of killed?

Answer 22

1. Provide weak or short lived immune response

May require boosters

Question 23

What type of vaccine consists of whole pathogens?

Answer 23

Killed

Question 24

Is a killed vaccine able to infect host cells?

Answer 24

No

Question 25

What types of vaccines require boosters?

Answer 25

Killed | Subunit or Toxoid

Question 26

What does a subunit vaccine consist of ?

Answer 26

Antigens (targets) that best stimulate the immune system or specific toxins that mediate disease

Question 27

What are the 3 methods of preparation for a subunit ?

Answer 27

1. Chemical extraction of pathogen 2. Recombinant DNA tech 3. Chemically synthesized

Question 28

What type of immune response does a subunit elicit?

Answer 28

Antibody responses

Question 29

What type of immune response does a subunit not elicit?

Answer 29

Cytotoxic T | So we do not make T-cells

Question 30

What type of antigens do we chose for subunit vaccines

Answer 30

Conserved antigens | They won't escape vaccine

Question 31

What is a major problem of subunit?

Answer 31

Pathogens that are antigenically diverse | Thye can mutate and escape the vaccine

Question 32

Why does a subunit not work for Malaria?

Answer 32

Malaria can change its outercoating

Question 33

How do we generate a subunit vaccine that works on a pathogen that changes?

Answer 33

We chose suface antigens so that even if the pathogen changes the surface of the spike protein sticks to the host

Question 34

When do we use a toxoid vaccine?

Answer 34

When a bacterial toxin is the main cause of illness

Question 35

Give an example of a toxoid vaccine

Answer 35

Diptheria or Tetanus

Question 36

How does tetanus harm us?

Answer 36

It secrets a toxin and the toxin causes paralysis | So we vaccinate against the toxin and not the bacteria

Question 37

What are the 2 new vaccine strategies?

Answer 37

1. Engineered | 2. DNA/RNA

Question 38

How does an engineered vaccine work?

Answer 38

Attach targets from a highly virulent pathogen to the surface of a weak pathogen

Question 39

Does an engineered vaccine infect the host?

Answer 39

Yes

Question 40

What type of vax technique so we dress up a pathogen to look like a more virulent pathogen?

Answer 40

Engineered

Question 41

What vaccine has no pathogen?

Answer 41

DNA/RNA

Question 42

How does a DNA/RNA vax work?

Answer 42

Inoculate w/ a gene encoding a pathogen or targer

Question 43

How does a recombinant vector vax work?

Answer 43

Introduce genes encoding microbial antigens into a non-cytopathic or attenuated virus/bacteria and infect individuals

Question 44

Does a rec vector generate a true infection?

Answer 44

Yes

Question 45

What type of immune response does a recombinant vector elicit?

Answer 45

Full complement immune response, including strong CTL responses

Question 46

Can we use engineered vaccines on health care workers and immunocompromised?

Answer 46

No, it is STILL an infection

Question 47

Is there any pathogenic machinery in an engineered vax?

Answer 47

No

Question 48

Give an example of a recombinant vector vaccine

Answer 48

VSV-EBoV J/J Astrazenica

Question 49

Give an example of DNA/RNA vax

Answer 49

Moderna | Pfizer

Question 50

What are 4 advantages to a DNA/RNA vax?

Answer 50

1. Elicit designer immune response 2. Easy to produce and purify 3. Stability 4. Low cost

Question 51

Theoretical concerns over DNA/RNA (2)

Answer 51

1. Potential for genomic integration into host chromosomal DNA and induce mutagenesis and insertional carcinogenisi AKA introduce into the wrong cells and create cancer 2. Potential for induction of ant-ds-DNA or antibodies against other nucelar antigens, leading to autoimmunity

Question 52

What type of vax uses our cell machinery?

Answer 52

DNA/RNA

Question 53

What does a killed usually consist of ?

Answer 53

Components often consists of surface molecules of pathogens that mediate host cell invasion

Question 54

How does a DNA/RNA vax work? 4 steps

Answer 54

1. Gene antigen of interest is cloned into a bacterial plasmid that is engineered to increase the expression of the inserted gene in mammalian cells 2. After being injected, the plasmid enters a host cell where it remains in the nucleus 3. Using the host cell machinery, the plasmid DNA directs the synthesis of the protein it encodes 4. The microbial protein may be presented in the context of MHC molecules to elicit T-cell responses