vaccines Flashcards
what cells does the IM memory involve
memory B cells, memory CD4+ T cells, memory CD8+ T cells and long lived plasma cells
what can memory CD8+ T cells do
kill immediately
what can memory CD4 +T cells do
produce cytokines
during 2y infection - which antibodies are produced first in the body
IgM AND IgG - more IgG
the pre existing IgG results in ability to clear infection during incubation periods
what can IgG do to the bacteria and its products
directly neutralise
can also mobilise phagocytes and complement
what does preformed IgA do
block the bacterial attachment to the mucous membrane
what can happen in diptheria
individual may clear the toxin through anti-toxin antibodies, but remain a carrier of microorganism
what have memory B ells already undergone
Ig class switching and hypermutation
what enhance properties do memory cells have
cell adhesion and chemotaxis
what is active immunity
protection produced by the hosts own immune system
usually permanent
what is passive immunity
protection transferred from a person or animal
wanes with time
how do active vaccines work
stimulate immune response to antigen through same pathways as natural infection
variolation
Exposure of an individual to the contents of dried smallpox pustules from infected patient
live attentuated
exposure to same organism with reduced virulence
what is an example of live attenuated vaccine
immunisation with cowpox protects from small pox
what are some features of inactive vaccines
cant replicate
not as effective
immune response primarily antibody based
multiple doses required
how can you make an inactive vaccine from a live pathogen
expose pathogen to
- heat
- irradiation
- chemical fixatives eg formalin
what are problems with this
can over or under inactivate
what is Poliomyelitis cause by
poliovirus
what is an adjuvant
Mixture of inflammatory substances required to stimulate immune responses to coadministered peptides, proteins or carbohydrates
what is a fractional vaccine
only part of the organism used in the vaccine
what is an example of a subunit vaccine
Hep B - surface antigen only
what are polysaccharide vaccines
inactivated
disadvantage of live attenuated vaccine
may cause infection in IC host
what is the salk polio vaccine
inactivated
what is the sabin polio vaccine
live attenuated
example of passive immunity
maternal antibody - IgG transplacental
breast milk contains IgA
Palivizumab
Monoclonal antibody produced against a single determinant of the RSV - provides passive immunity
