Defence and vaccination against infection Flashcards
4 evasions of host defences
- Avoid complement activation
- Avoid phagocytosis
- inhibit host cell signalling pathways
- resist or evade phagocyte killing mechanism
both B and T cell can mature into 2 categories of cells
- effector cell
2. memory cell
2 types of immunisation
active
passive
active immunisation=
to induce a state of immunological readiness so a first interaction with a pathogen is treated like a second infection by the same pathogen
passive immunisation=
to transfer pre-formed immunological mediators (antibodies) into a person to generate a state of enhanced immunity
e.g of passive vaccinations (5)
tetanus gangrene snake bite hep B rabies
2 types of active immunisation
live vaccines
non-living vaccines
2 types of live vaccines
naturally attenuated
artificially attenuated
non-living vaccines can be three things
killed whole organism
antigenic components of the organism
DNA from the organism
what type of virus is small pox
DNA ds virus
immunisation against small pox=
vaccinia virus
4 reasons eradication of small pox was possible
- exclusive to humans
- no hidden carriers
- only one serotype
- vaccination 100% successful
what type of virus is polio virus
positive strand ss RNA
structure of polio
icosohedral
2 types of polio vaccines
inactivated (dead)
attenuated (live)
disadvantage of the inactivated polio vaccine
does not induce local (gut) immunity
disadvantage of the attenuated polio vaccine
Can cause vaccine-induced poliomyelitis
e.g of 3 subunit vaccines
diptheria
tetanus
pertussis
(DTP)
subunit vaccine=
vaccines made of components of an organism
what might a subunit vaccine require
Adjuvants
what can adjuvants do (3)
- Inducing inflammation
- boost innate immunity
- Provide long-lasting depot of antigen
5 routine vaccinations
DTP Hepatitis B Haemophilus influenzae type B measles (MMR) poliomyelitis (OPV or IPV)
what maternal antibodies are passed over via colostral
IgA
what maternal antibodies are passed over via the placenta
IgG
2 naturally attenuated live vaccines
smallpox (variola) and cowpox (vaccinia)
name 5 vaccines given at 2-6 months
polio diphtheria pertussis tetanus meningitis
3 vaccines given at 12-18 months
measles
mumps
rubella
