vaccines Flashcards
absence of viral replication, rarely granted by passive transfer of antibodies
sterile protection
the first goal of vaccines is to generate neutralizing antibodies, which can (4)
bind to free virus to direct neutralization
direct complement mediated virolysis
complement-mediated phagocytosis and inactivation
why don’t viruses evolve surface structures to fail to elicit neutralizing antibodies
viruses with strong neutralizing response must have been under evolutionary pressure to
be transmitted quickly between hosts before antibodies can coat progeny virus
and they must not rely on reinfection of same individuals
or they may code response elciting regions in loop regions that can sustain extensive variation
advantages inactivated virus vaccine
no genetic mutation
safe for immuno compromised
gene innoculation can be improved by inclugind
genes encoding cytokines and costimulatory molecules
inactivated virus vaccines elcit ____ but not ____
circulating antibodies buy not mucosal immunity
disadvantages inactivated virus vaccine
fails to ellicit gut immnity
requires parental admin
expensive
requires boosters
must ensure antigenic potency and inactivation
advantages live attenuated vaccine
inexpensive and easy admin
induces systemic and secretory immunity
induces herd immunity
longer lasting more complete response
mucosal immunity
full range of gene products expressed
DNA inoculation
DNA taken up into cells
proteins expressed
provide secreted antigens
humoral and cellular immunity develops without inherent risk in adding any virus/pathogen
disadvantages live attenuated virus vaccine
can mutate to more virulent strain
less reliable in tropical climates (storage)
residual pathogenecity
can spread from vacinees
interference from related viruses
immune evasion strategies may still be present/develop
