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57 Cards in this Set
- Front
- Back
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what are the two basic types of vaccinations?
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passive and active immunization
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what is the goal of passive immunization?
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not to active the individual's immune system, but rather to introduce protective immune cells or molcules that were generated by active immunization in another organism
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what is the goal of passive immunization?
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to generate an active immune response to the antigen leading to protective
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what is the purpose of an adjuvant? how?
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to aid in the immune response to the vaccine by either concentrating the vaccine at the site of introduction to limit spread or to non-specifically induce inflammation at site of introduction.
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with which type of vaccine does adding an adjuvant NOT concentrate the vaccine at the site of introduction to limit spread?
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live-attenuated
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what type of inflammation is produced by adjuvants with their respective vaccine?
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antigen independent inflammation
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what is freund's complete? what are the problems with this?
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a emulsion of killed mycobacteria and mineral oil. This is very strong and can be fatal and cause septic shock.
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what are the two adjuvants that are curently being used for humans? why these two?
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alum and MF59 (emulsion of squalene, oil, and water). These two are weaker, but they are safe and have no side effects.
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what are the four normal forms of vaccines?
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killed or inactivated vaccines
live-attenuated vaccines subunit-vaccines conjugate vaccines |
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what are the three ways in which a killed vaccine can be produced?
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chemical tx (formaline)
heat killing (autoclave) irradiation (create unrepairable nucleic acid damage) |
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how does a killed vaccine work?
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the bacteria is killed and the virus is inactivated, but each can still stimulate the immune system.
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what are the pros and cons of killed vaccines? give some examples
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pros: safer than liver-attenuated
cons: large quantities of inactivated pathogen needed suitability of genome for irradiation health hazards of chemicals involved in killing/inactivation Ex: RIP always R- rabies I- influenza P- Polio Salk A- Hep A |
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what is the difference between killed and live attenuated vaccine?
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killed: ability of a virus/ bacteria to cause an infection
live: ability of a virus/ bacteria to cause a disease. |
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how is a live-attenuated vaccine created?
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removed by manipulation of the genome either by forced evolution of a virus in culture and direct manipulation of viral or bacterial genome by molecular biological techniques.
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for live-attenuated vaccines, how does it undergo forced evolution?
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the pathogenic virus is grown in human cultured cells --> those cells are used to infect monkey cells --> the virus acquires monkey mutations --> virus no longer grows well in human cells and is now a fabulous vaccine
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how do recombinant techniques attenuate the virus or bacteria?
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all the genes involved in virulence (disease), but not required for growth are removed
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what are the pros and cons of live vaccines? give some examples?
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pros: best at inducing an immune response
cons: reversion mutants (sabin polio)- can cause paralysis and neurological infections (oral form) called vaccine derived polio virus (VDPV) ex: Measles, Mumps, Sabin polio, yellow fever- think MMR |
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where are humoral immune responses typically made against?
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proteins/ lipids on the exterior of virus particles of bacterial capsules.
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how are protein subunit vaccines produced?
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genes for proteins are isolated and their encoded proteins are produced in large quantities by recombinant techniques
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how are polysaccharide subunit vaccines formed?
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capsules of pathogenic bacteria are purified and used as a subunit vaccine.
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what is an example of protein subunit vaccines? what are the problems in production?
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ex: HBV vaccine (HBsAg)
problems: polysaccharide subunit vaccines elicit a T-independent response that is poor in children under 18 months |
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what is the most successful bacterial subunit vaccine? how are they inactivated? Give examples
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Toxoids- inactivated by tx with formalin.
ex: tetanus toxoid and diphtheria toxoid DTP DTaP |
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what does the aP component of DTaP contain?
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inactivated pertussis toxin and one or more pertussis antigens (including hemagglutinin, pertactin, and fimbrillar antigen)
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how does a DNA vaccine work?
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plasmids containing a cDNA encoding a protein antigen is inoculated into subject. Cells take up the DNA and begin to express the encoded protein which can then be presented to T cells. The APCs are removed and transfected with cDNA containing plasmid. The cells are then reintroduced into the subject to present the expressed protein from plasmid.
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How do plasmids grown in bacteria induce an innate immune response? what is the benefit?
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the plasmids grown in bacteria are rich in unmethylated CpG nucelotides that are recognized by TLR9 (pattern recognition receptors) on macrophages and other cells. The benefit of this is that the innate immune response will enhance the adaptive immune response and overall response to the antigen.
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how much of the pathogen is used in a DNA vaccine?
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DNA complete w/ a promoter and encoding a single protein
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what are DNA vaccines in use/ trial as?
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Tumor vaccine
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what are viral vectors?
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viral genomes that are modified to include the expression of a protein of interest from the pathogen to be vaccinated against.
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recombinant viruses act in a similar manner to what other type of vaccine? what makes recombinant viruses diferent?
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similar to live-attenuated vaccines
different: in recombinant viruses, only some of the genes expressed are from the pathogen of interest. |
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how is recombinant virus formed?
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a gene from a pathogen is inserted into the genome of a harmless virus which creates a recombinant virus.
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how can you make a T-independent subunit vaccine into a T-dependant vaccine?
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by making a conjugate vaccine
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how is a conjugate vaccine formed?
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a viral/bacterial target is fused or conjugated to a harmless but immunogenic protein that elicits a T cell dependent response.
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what is the difference between conjugate vaccine and recombinant virus?
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recombinant involves a harmless VIRUS + pathogen
whereas a conjugative vaccine includes a harmless PROTEIN + pathogen |
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How does a conjugative vaccine work?
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1) bacteria is fused to a harmless protein
2) causes an APC to form on the B cell and alert the T cell 3) T cell then helps the B cell to produce antibodies against the virus/ bacteria + protein |
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what is an example of conjugate vaccines?
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H. influenza B
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what do immune responders in intestines and ENT regions induce and provide?
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local memory and defense...
as opposed to systemic |
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which entry will be more likely to induce systemic response/ memory?
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skin/bloodstream
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what is not generally protected with intramuscular injections?
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entry of pathogens through ENT or intestines
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where do most infectious agents enter the body?
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eating or breathing
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why is it difficult to immunize infants? (microbiologically speaking)
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1) poor T-independent antibody production
2) lower antibody responses to T-dependent protein vaccines 3) short-lived antibody responses to vaccines 4) inhibitory effect of maternal antibodies 5) altered T cell responses. |
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Specifically, which cells are vital responders to blood borne T-independent polysaccharide antigens?
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splenic, marginal zone B cells.
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when is the architecture of the spleen developed?
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about 2 years old
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why are children under the age of 2 poor T-independent antibody producers?
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because the specific B cells need to have a T-independent response may not exist or be limited in their response to T-independent antigens
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T/F
Germinal centers are neither delayed or accelerated in appearance compared to older children. |
FALSE
Germinal centers are delayed in appearance compared to older children. |
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what does a delay in appearance of germinal centers cause?
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lower antibody responses to T-dependent protein vaccines
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T/F
plasmablasts in infants fail to form appropriately and thus fail to create a long-lived antibody response to vaccines |
FALSE
plasmablasts form appropriately, but fail to SURVIVE as long as in older children/ adults. |
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T/F
Maternal Abs will inhibit infant Ab production, but not T cell responses. |
true
the example give here is the measles vaccine |
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why do infants have an altered T cell response?
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neonatal dendritic cells produce different cytokines than adult dendritic cells to the same antigens. Infants show Th2 skewed responses.
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what type of vaccines induce the best response in infants compared to other vaccine types?
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live-attenuated vaccines
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what is Herd immunity?
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if vast majority of a pop is vaccinated/ immune to a pathogen, then there are fewer individuals that can become infected and expose those that are also not immune.
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why doesn't the US use BCG?
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because it will cause a full infection/ disease and is not attenuated
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when does a reaction to DTaP occur?
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after 4th or 5th shot within 2 days of the shot
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what percentage of children get a fever over 101 after getting a DTaP vaccine?
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5%
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what are the chances of a child getter a fever of greater than 104 after getting a DTaP vaccine? How many of those fevers cause convulsions?
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- 1 in 3,000
of the 1 in 3,000--> 1 in 14,000 have convulsions caused by fever only |
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what is the reaction fever from the DTaP vaccine in response to?
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immune response to vaccine/adjuvant
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what does every state require for a child to go into daycare?
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the first 3 DTaP shots
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what are T-independent responses against?
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Polysaccharides
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