Term
| Why do you need to get DTaP so many times? |
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Definition
| It is a protein vaccine - so it is a bit of the bug, not the whole bug. Therefore, it isn't good at immunogenenics so must give often |
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Term
| Why do we have to wait until a child is 12 months old to get the MMR vaccine? |
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Definition
| Because it is a live attenuated virus, and before 12 months the immune system isn't developed enough to deal with a live virus |
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Term
| What is the concept behind live related vaccines? |
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Definition
You immunize with a closely related, but much less pathogenic organism
Then you count on immunological cross-reaction in response |
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Term
| What's the best example of live related vaccines? |
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Definition
This was the first used vaccine.
Leishmania major gives you a skin ulcer that isn't deadly. However, Leishmania donovani is deadly.
If you had Leishmania major, you wouldn't get donovani... so they scraped the major off of skin ulcers and spread it on backs of children so they could avoid getting donovani. |
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Term
| What is the best known example of a live related vaccine? |
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Definition
Cowpox
They noticed that milkmaids, who had had cowpox never got small pox. So they isolated material from active cowpox and injected them into a boy... then exposed him to smallpox. He was protected. |
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Term
| What are the positive sides of live related vaccines? |
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Definition
Very strong protection
Persistent antigen source
Lots of antigens |
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Term
| What are the negatives of live related vaccines? |
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Definition
Dangerous (live bugs could cause problems)
Lack of availability of non pathogenic relatives to common pathogens |
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Term
| Explain the concept behind live attenuated vaccines |
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Definition
| You weaken the pathogenicity and growth ability (attenuate) a pathogen to allow for activation of the immune response, but not disease |
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Term
| How do you attenuate pathogens? |
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Definition
Chemically
With radiation
By molecular manipulation |
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Term
| What are some examples of live attenuated vaccines? |
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Definition
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Term
| What are the positives to live attenuated vaccines? |
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Definition
Persistence
Full spectrum of antigens
Antibody and cell mediated activation
Long lasting protection (so limited boosting required) |
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Term
| What are the negatives to live attenuated vaccines? |
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Definition
Risk of disease (polio)
Need to make sure you don't give them to immunodeficient patients (particularly in children...important to look for the 10 signs of immunodeficiency) |
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Term
Explain the concept behind killed organism vaccines.
Give examples |
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Definition
The pathogen has been killed by heat or chemicals
Examples are IPV (Salk) or H1N1 |
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Term
| What was the deal with the Salk screw up? |
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Definition
| The salk wasn't appropriately killed so 2000/4000 children that were vaccinated came down with polio |
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Term
| Positives of killed organism vaccines |
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Definition
| They are very safe as long as the pathogen is sufficiently killed by heat (causing proteins to denature and be damaed) |
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Term
| What are the negatives of killed organism vaccines? |
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Definition
No persistence
Limited cell mediated immunity
Antigens are damaged by the treatment used to kill the pathogen
Often need an adjuvant to boost the response |
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Term
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Definition
It allows the vaccine to persist and convince the immune system that there is danger
It is usually a mixture of oil and something that stimulates a minor inflammatory response to indicate danger |
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Term
| To get a good immune response you need ___ and __. |
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Definition
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Term
| Explain the concept behind pure protein (sub-unit) vaccines. |
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Definition
| Instead of immunizing with the toxin, you make a modified pure protein (aka a toxoid) and use that instead. Or you use a pure protein |
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Term
| Give examples of Pure protein vaccines |
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Definition
Tdap --> tetanus (toxin), diptheria (toxin), pertussis (pure protein)
HPV (pure protein) |
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Term
| Why can't you get HPV from the HPV vaccine? |
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Definition
| because it is a pure protein vaccine |
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Term
| What are the positives of pure protein vaccines? |
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Definition
- very safe
- easily transported and stored
- used for organisms that produce potentially fatal toxins
- can't get the disease from the protein |
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Term
| What are the negatives associated with pure protein vaccines? |
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Definition
- they are weak immunogens
- they have no spectrum of antigens
- They are transient (have no persistence)
- They need adjuvants
- They need boosting |
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Term
| Explain the concept of viral vector vaccines. |
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Definition
You express the gene of interest in a viral vector in the host. The viral veto is non-pathogenic and relatively short lived
Immunity is then acquired to both the vector and target |
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Term
| Give examples of viral vector vaccines. |
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Definition
- GSK ebola vaccines
- The Canadian vaccine Ebola gene in VSV |
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Term
| Positives of viral vector vaccines. |
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Definition
Very safe
persistence
activation of antibodies and cell mediated responses |
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Term
| Negatives of viral vector vaccines |
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Definition
| limited spectrum of antigens |
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Term
| Explain the concept of polysaccharide conjugate vaccines |
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Definition
In order to get antibody against a polysaccharide, you link polysaccharide to protein for T cell activation.
Because the t cells only recognize/respond to peptide! |
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Term
| Describe Dendritic cell uptake of polysaccharide/protein conjugate and presentation of peptides to t cells. |
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Definition
- We have a polysaccharide/protein conjugate.
- It is similar to a glycoprotein in the natural immune response
- Dendritic cell responds to the protein part, and stakes it up into a phagosome
- lysosome merges --> phagolysosome
- protein and polysaccharide get broken down
-This merges with a vesicle with class II MHC
- A peptide from the protein is brought to the surface! |
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Term
| Describe B cell uptake of polysaccharide/protein conjugate presentation of peptide to T cells |
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Definition
- Some B cells respond to the protein (b/c it has protein)
- Some B cells will respond to polysaccharide! B/c there are antibodies on the surface of b cells that aren't restricted to only recognizing protein |
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Term
| Which B cells do you want to become plasma cells later on? |
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Definition
| The B cells that recognized polysaccharide, because they will make antibody to the polysaccharide!! |
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Term
| What happens when the B cell surface antibodies recognize polysaccharide? |
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Definition
-They take the protein/polysaccharide conjugate in via receptor mediated endocytosis.
- Lysosome merges and it gets broken down into bits in the endolyosome
- then it merges with a vesicle that has class II MHC
- and it pops the PEPTIDE in he groove and shows it to the T cell.
Antibody recognized polysaccharide, but shows the T cell the peptide |
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Term
So... at this point:
Have an activated B cell that has antibody that is specific for the polysaccharide.
It activates a CD4 T cell that has already been shown the peptide of this protein/polysaccharide conjugate by the dendritic cell.
Now what happens!? |
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Definition
| CD4+ T cell produces IL-4 and co-stimulation occurs so that it can help a B cell that is specific to the polysaccharide |
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Term
| What do we used polysaccharide conjugated vaccines for? |
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Definition
| organisms that have surface polysaccharide coats |
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Term
| Give examples of polysaccharide conjugated vaccines |
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Definition
- pneumococcal polysaccharide (conjugated to Diphtheria toxoid)
- Hib polysaccharide (conjugated to Diphtheria toxoid) |
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Term
| What are the positives and negatives of polysaccharide conjugated vaccines |
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Definition
-Activate good antibody response to polysaccharide residues.
- They are weakly immunogenic and have limited cell mediated immunity (but don't need this really b/c you want antibody) |
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Term
| The more serious the vaccine, the ___ likely you are to use a live attenuated vaccine |
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Definition
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Term
| What is the most common cause of gastroenteritis in children? |
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Definition
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Term
| Why was thimerosal used in vaccines such as H1N1? |
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Definition
| it prevents staph growth (could be fatal) |
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Term
| Explain the concept of passive immunization. |
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Definition
| You provide antibody for direct protection. Usually give this after infection. |
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Term
| What are some examples of passive immunization? |
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Definition
-Anti-toxoid: If you have tetanus, rabies or botulism --> given an antibody against the toxin
-Anti-venom: if you get a spider or snake bite
- Prior to infection --> respiratory syncytial virus (RSV) you give a monoclonal antibody to F protein to prevent infection |
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Term
| Positive for passive immunization |
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Definition
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Term
| Negatives for passive immunization |
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Definition
- Doesn't activate long term protection
- Serum sickness from immune complexes to horse Ig!! |
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