paediatric immunisations Flashcards
aim of immunisations
control communicable diseases by:
- preventing onset of disease by primary prevention using pre-exposure
- alter course of disease to prevent or limit its consequences by secondary prevention
how do vaccines work
vaccines teach the immune system to recognise bacteria and viruses before the individual encounters them as potential pathogens which allows the body to fight the pathogens
mechanisms of immunity
- active immunity
- passive immunity
- herd immunity
active immunity refers to
the process of exposing the body to an antigen to generate an adaptive immune response, the response takes days/ weeks but the response tends to be long lasting
Active immunity can be
naturally acquired or acquired by artificial immunisation
antigens are
recognised by the immune system which generates a response resulting in the production of antibodies, the antibodies form antibody-antigen complexes which alerts other immune cells
how are antibodies produced
B cells= humeral immune system, produced in the bone marrow and are triggered to produce antibodies when they encounter a foreign antigen
T cells= cell-mediated immune system, produced in the thymus, CD4 and CD8 T cells which orchestras response of immune system by binding to other cells and sending out signals
passive immunity
process of providing IgG antibodies to protect against infection which gives immediate but short lived protect
passive immunity can be
natural or acquired
natural passive immunity
transplantal transfer, antibodies are transferred to the foetus via the placenta but only protect the neonate for a certain period of time
maternal antibodies protect against
measles, rubella and tetanus but not polio or pertussis
acquired passive immunity
artificially acquired by the transmission of IgG antibodies from another person or animal
types of acquired passive immunity
Hep B, rabies, varicella zoster, diphtheria, botulism
advantages of passive immunity
- rapid action
- can be used post-exposure
- can attenuate an illness
- can control outbreaks
disadvantages of passive immunity
- short term protection
- short term window
- blood derived
- hypersensitivity reaction
- expensive
herd immunity
a form of immunity that occurs when the vaccination of a significant proportion of a population provides a measure of protection to individuals who have not developed immunity