10 Flashcards
what is the supply chain used to make vaccines cold
cold chain
active vs passive immunisation
passive is using ABs for shrt term immunity and emergencies
inactivated vacc
contain bacteria or virus that has been heat or chemically inactivated
requires multiple doses
produces weak immune response
inactivated vaccines examples
polio, rabies, hep A, flu
live attenuated vaccines maintains __ but loses __
antigenicity but loses pathogenicity
eg of live vac
mmr, smallpox, varicella, yellow fever, rotavirus
subunit, recombinant, polysaccharides and conjugate vacc
recombinant contains the genes encoding specific antigen
conjugate vac contains a weak and strong antigen
these can be protein (spike) or peptide or polysaccharides based
what are toxoid vacc
toxic effects are removed by removing the exotoxins and endotoxins with formaldehyde at a certain temp
how do toxoids give immunity
by stimulating anti toxoid antibodies
they also bind to the toxin and neutralise its toxic effects
toxoid contains
booster and adjuvant
viral vector vaccines
viral vector contains
DNA spoke protein of the virus
how is viral vector vaccine made
spike protein genetic material extracted and inserted to viral vector. then injected to human and vector enters cekk. the spike proteins are created and recognised by immune system.
mRNA vaccines is made
mRNA surrounded by tiny lipids
6 components of vaccines
immune antigens
suspension fluids
adjuvants
preservatives
stabilisers
emulsifier /surfactant
eg of preservatives in vaccines
FORMALEDHYDE, THIMEROSAL, 2 PHENOXYETHANOL
which preservative in vaccines can trigger hypersensitivity
thimerosal. used in place of BAK
both fungistatic and bacteriostatic
adjuvants role
induce more potent immune response.
2 groups adjuvants
vaccine delivery systems
immunistimulatory adjuvants
vaccine delivery system adjuvant role
nano and micro particles that concentrate and attack antigen
immunostimulatory adjuvant role
immunopotentiators activate innate immunity directly by cytokines or through pattern recognition receptors
eg of adjuvants
aluminum hydroxide or phosphate
complete friends adjuvant contains heat killed mycobacteria suspended in oil (has severe side effects)
o/w and w/o emulsions are v toxic
montanide
w/o emulsion adjuvants are called
incomplete Freunds adjuvant and are v effective but cause cutaneous reactivity
eg of stabilisers
MSG, gelatin (protects from heat), sorbitol, buffers
lyophilised vaccines an stabilisers
lyophilised vaccines don’t need stabilisers
eg of surfactants
also used as adjuvants
sorbitan esters, lecithin, manned elates
lipopolysac from g neg outer membrane
saponins
DDAB
midstream bioprocessing filtrations
cake/alluvial fiktration
tangential flow filtration
centrifugation
downstream bioprocessing
chromtatgraphy
ultrafiltration
precipitation
enzyme digest
polysaccharides conjugate vaccines are conjugated to
non toxic non reactogenic carrier proteins
key contaminant in viral vaccine process
carryover nucleic acid from lysed cells –> benzonase endonuclease is used to degrade nucleic acids like RNA and DNA of host cells together with chromatographic separation
processing of viral vector vaccine
cell lysis and clarification via filtration, nuclease treatment and ultrafiltration then final sterile filtration
mrna vaccine inactivation of virus particles through
formalin
but must be removed
mrna purified via
tangential flow filtration
because formulated vaccines can’t be filter sterilised,
adjuvant and purified antigens are filtered and sterilised separately then aseptically blended
lyophilisation process has 7 steps
same as before
issues w stoppers during lyophilisation
traps moisture, lubrication during closing, possible source of contamination
potency of vaccine by immunoassay
for which vaccines
polio, hav, recombinant and subunit vacc : hep A and Hep B
antiigen content is measured by __ in immunoassay
ELISA
ELISA may still yield a positive result in case of degraded antigen so also use
HPLC, SDS page
ow is potency of live vac tested
virus titer using in vitro cell culture
cells infected with various dilutions of vaccine
cell death quantified
polysaccharides vaccine potency
measured by polysaccharides content, size, purity, degree of adsorption
manufacturer QC test consists of
antigen identity, content, size, purity, sterility and endotoxins,
if toxic compounds eg formaldehyde are used they mustt be removed
for inactivated vaccines test for residual live virus or bacteria
