Vaccines

Question 1

The best vaccines take advantage of which aspect of your immune system?

Answer 1

the ability of your adaptive immune responses to develop memory and fast, secondary responses

Question 2

Why do all vaccines work differently

Answer 2

because different pathogens have different mechanisms of causing disease and injury

Question 3

How can a bacterial pathogen cause disease

Answer 3

through toxins that can damage neurological functions, caussing diarrhea and cell lysis

Question 4

What are the two inflammatory responses

Answer 4

systemic
chronic

Question 5

example of systemic inflammatory response

Answer 5

sepsis (loss of b.p,, organ failure, death)

Question 6

example of chronic inflammatory response

Answer 6

permanent tissue damage

Question 7

what is cross-reactivity

Answer 7

antibodies against bacteria cross-react with structures in the host and cause damage

Question 8

How might a virus cause disease

Answer 8

virus can kill cells – permanent damage

virus can weaken the host – host can be susceptible to secondary infections (often from bacteria)

virus can trigger unwanted immune response – cytokine release syndrom (similar to sepsis)

Question 9

Sometimes, a vaccine can make a person feel unwell, is that from the pathogen in the vacine or something else?

Answer 9

could be cytokines

Question 10

Some vaccines induce T cell mediated and B cell mediated immunity, what does that mean

Answer 10

you will have memory B cells, memory CTLs, memory T helper cells that can help macrophages and B cells

e.g: live virus of measles

Question 11

Some vaccines only induce B cell mediated immunity, what does that mean

Answer 11

you will have active plasma B cells that secrete antibodies
AND
might also have memory B cells and memory T helper cells that can help B cells

e.g Tetanus / Influenza

Question 12

What are the ideal attributes of a vaccine

Answer 12

Safety
Effectiveness
Easy to vaccinate
Low cost
Rapid, reliable production protocols
High yield during production
Stability / Distribution (storage)

Question 13

What are the antigen components of an inactivated influenza virus

Answer 13

WIV (whole inactivated virus)

Virosomes

Split

Subunit

Question 14

What are virosomes

Answer 14

influenza virus envelopes that have been formed again

Question 15

What is split

Answer 15

process where the virus is disrupted with detergent, containing all the virus proteins, then the virus RNA is lost

Question 16

What is subunit

Answer 16

puritifed H and N proteins after splitting

Question 17

What are the main problems with the convential approach of making a vaccine

Answer 17

needs cell/egg based tech
can run out of supplies
slower process and costly
need dedicated facilities

in contrast, mRNA vaccines make a promising alternative

Question 18

All vaccines are formulated to include standardized amounts of …. from the influenza viruses

Answer 18

hemagglutinin

Question 19

Advantages of mRNA vaccines over attenuated/killed/subunit/DNA vaccines

Answer 19

mRNA is non-infectious (can’t get sick)
only a portion of the genome is used
mRNA doesn’t integrate into chromosomes/genes

Question 20

mRNA can be formulated with carrier molcules for in vivo delivery, what does this allow

Answer 20

rapid reuptake and expression in the cytosol

Question 21

If using a cell-based system to make mRNA vaccine, the desired mRNA would have to be

Answer 21

purified from the rest of the cell RNA

Question 22

Cell free in vitro transcription reactions allow for the synthesis of what

Answer 22

single species of RNA

Question 23

Explain the process on how to make mature RNA starting from dsDNA

Answer 23

dsDNA transcribed to ssRNA, then add a 5’ cap and Poly A tail
=== mature RNA!

Question 24

the dsDNA template can be a

Answer 24

linearized plasmid DNA or a PCR DNA product

Question 25

various modifications can be made during the synthesis of RNA, which is

Answer 25

add poly A tail and caps use modified nucleosides to improve RNA stability introduce specific mutations to make protein products more stable replace rare codons

Question 26

There are two main types of mRNA vaccines

Answer 26

Conventional (non-replication) mRNA vaccines Self-replicating mRNA vaccines

Question 27

What are Conventional (non-replication) mRNA vaccines

Answer 27

they have ORF of the target antigen, 5' cap. 3' UTR, poly A tail Doesn't replicate itself (1 copy = 1 protein) produces antigen temporarily

Question 28

What are Self-Relication mRNA vaccines

Answer 28

they have ORF of the target antigen have RDRP (viral rep. machinery) lets mRNA to make more copies of itself makes more antigen over time (longer and stronger response) mimics viruses

Question 29

Now with the RNA vaccine, what do our cells have to do

Answer 29

they must make protein antigen before our immune system can respond to them

Question 30

The expression of that protein are generated as

Answer 30

a secreted, trans-membrane protein / intraceullar protein that is displayed on MHC

Question 31

Why is mRNA delivery into cells challenging?

Answer 31

Because mRNA is large and (-) charged, so it cannot cross the lipid membrane easily

Question 32

What is the goal of mRNA delivery in vaccines

Answer 32

To get mRNA into the cytoplasm, where it can be translated into protein (antigen)

Question 33

What are the two main methods of mRNA delivery

Answer 33

Ex vivo (outside the body) In vivo (direct injection into the body)

Question 34

How does Ex vivo mRNA delivery work

Answer 34

mRNA is inserted into dendritic cells in the lab, which are then injected back into the patient

Question 35

What are the pros of ex vivo delivery

Answer 35

high control over which cells take up the mRNA high transfection efficiency

Question 36

What are the cons of ex vivo mRNA delivery

Answer 36

time-consuming, labour intensive and costly

Question 37

How does in vivo mRNA delivery work

Answer 37

mRNA is directly injected into the body (often via nanoparticle)

Question 38

What are the pros of in vivo mRNA delivery

Answer 38

Fast, cheaper, and easier than ex vivo

Question 39

What are the cons of in vivo mRNA delivery

Answer 39

less control over which cells take up the mRNA

Question 40

What is transfection

Answer 40

process of artificially introducing DNA / RNA into eukaryotic cells (not viral infection)

Question 41

the DNA and RNA that went in via transfection is replicated, true or false

Answer 41

false, because it's only expressed for a limited of tie

Question 42

what are the some ways to get RNA / DNA into the cell (transfection)

Answer 42

Electroporation -- make mambrane more permeable Lipid base reagents -- cost nucelic acid while forming micelles

Question 43

can electroporation be done in vivo?

Answer 43

yes it's injected into tissues and the electric field is applied to move the nucleic acid ito the tissue (not practical)

Question 44

Lipid nanoparticles (LNP) have become one of the more commonly used mRNA delivery tools. It can consist of

Answer 44

- ionizable cationic lipid --- for self assembly and release mRNA into cytoplasm - polyethylene glycol (PEG) --- increase half-life - cholesterol --- to stabilize - natural phospholipids --- support bilayer