Vaccines Flashcards
pandemics
an epidemic that spreads through human populations acorss a large region e.g. a continent or worldwide
epidemics
a occurence of an infectious disease within a given population at a particular time. it is restructed to one locale
Types of vaccine
Live (do not cause disease, Killed (by heating or chemicals), subunit (proteins or polysaccharides), naked DNA (makes proteins after injection
what is formaldehyde detoxification
it abolishes the toxicity of the protein and preserves its immunogenicity. It cross links amino groups in proteins and other nearby N atoms through a CH2 linkage. It cross links between proteins and within proteins
problems with formaldehyde detoxification
Over cross-linking could cause abolishment of immunogenicity (must retain antigenic structure); there is bacth to bacth variation; there can be reversion (crosslinks become undone); requires access to pure toxin at first
conjugate vaccines
Polysaccharide vaccines have large diversity and have poor long term memory. Alone a polysaccharide cannot enter the MHC class I or II pathway but can be linked with a protein to produce a conjugate vaccine which boost the antibody response as the conjugate can enter the MHC II pathway (endosomal)
what is a adjuvant
an ingredient used in vaccines that help create a stronger immune repsonse. They generate a more potent antibody and T cell response. They are used with subunit vaccines
Reverse vaccinology
looks at the genome for conserved proteins on the surface of bacteria that can be used as targets
Depot effect adjuvant
where the antigen is sequestered at the site of injection and becomes released over time. proteins can either be encapsulated in a slowly degraded vesicle or the adjuvant forms a gel like matrix and the antigen is bound to this by electrostatic interactions and is slowly released over time. For example, liposomes (encapsulate antigen in double bilayer) and aluminium salts that fomr a gel like matrix. Tetnus and anthrax
Delivery vehicles adjuvant
involves targeting the antigen to immune cell e.g. APCs. They force the antigen down the MHC I or II pathway by attaching particles to the vaccine that allow uptkae by APC or by using liposomes that can deliver antigens into the cytosol
immune stimulators adjuvant
they target cells of the innate system to produce cytokines that will mature the adaptive system. They stimulate the innate immune system by PAMPs (LPS and lipid A - a TLR agonist)
