immunity and autoimmune Flashcards
what is active immunity
involves immune response and production of antibodies
long lasting
what are the types of active immunity
natural
artificial
what is natural active immunity
when get infected by pathogen and antibodies are produced
what is artificial active immunity
injected with dead or weakened pathogen
antibodies are made that are complementary to antigens
what is passive immunity
when receive antibodies and dont have to make them ourselves
not long lasting (memory cells not produced)
but is more immediate
what is natural passive immunity
antibodies transmitted from mother to baby through placenta or breastmilk
what is artifical passive immunity
antibodies are transfused
blood transfusions
injected into people (not like vaccine)
how do vaccines provide immunity
- vaccine has antigens
injected into blood - stimulates primary response
- produces antibodies
- memory cells produced
- 2nd exposure memory cells rapid divide to plasma
- plasma produce antibodies
- pathogen destroyed before symptoms
- booster vaccines give longer lasting immunity
criteria for successful vaccine programme
infrastructure:
- resources to produce/store/transport
administration:
-need trained healthcare workers
availability:
-affordable and available in large amounts
few side effects:
-for better public acceptance
herd immunity:
- vaccine majority
what is herd immunity
when large proportion vaccinated
most people immune so cant transmit to others
less chance non vaccinated coming into contact with pathogen
less infected
why is mass vaccination and herd immunity important
prevent epidemics and pandemics
not possible vaccine everyone in large population eg babies or people with compromised immune system
why might vaccine not eliminate disease
pathogen mutation:
-cause antigenic changes make vaccines ineffective
pathogen variety:
-so many varients hard to make universally effective vaccine
vaccine objections:
- people not get at misinformed or religious/ethical objections
what is antigenic variability
antigens no longer recognised by immune system
memory cells produced from one strain not recognise from another strain
what can we do to provide more protection
change vaccine frequently specific to new strains
what is autoimmune disease
immune system attacks healthy cells as things they are foreign
