Vaccination

Vaccination

1. types of immunity

   • Active =achieved by activation of the immune system =long term.
     • 1.natural =you get the disease, your immune system responds =gives immunity
       • 2.artificial =immunity as a result of Vaccination (deliberate & medical intervention)
   • Passive =achieved by exposure to antibodies =short term
     • 1.natural =antibodies pass via placenta or breast milk
       • 2.artificial =Vaccination of antibodies (deliberate)

2. Vaccination is a deliberate exposure to antigenic material, so immune system manufactures antibodies & memory cells, to provide long-term immunity. (injection/ oral/ or nasal spray)

   • antigenic material used :
     • ~a dead pathogen e.g. typhoid & cholera
     • ~a harmless attenuated (weakened by the heat) e.g. measles & TB
     • ~whole, live microorganisms. usually one that is similar to the real pathogen e.g. small pox vaccine
     • ~the antigen e.g hepB
     • ~the harmless version of the toxin (called toxoid) e.g. tetanus

3. Herd vaccination

   • =using a vaccine to provide immunity to almost all of the pop at risk ->if enough people are vaccinated =pathogen can no longer be spread through the pop.
   • ~to eradicate all or almost all, the pop must be vaccinated ->small pox was eradicated as 80-85% of pop were vaccinated
   • ~estimated that if 95% had measles vaccine =would be eradicated

4. Ring vaccination

   • =vaccinate all people within an area/ perimeter ->to try to contain the pathogen
   • ~control the spread of pathogens
   • ~livestock

5. Control of epidemics

   • ~some pathogens can undergo genetic mutations which change their antigens, the memory cells produced by vaccination may not recognise the new antigens =the pathogen may be transmitted, & the incidence of the disease increases.
     • ~certain pathogens, such as influenza virus, are relatively unstable & regularly undergo changes in their antigens =epidemic may arise.
       • ~threats from epidemics can be monitored=enable health authorities to prepare ->stockpile suitable vaccines & vaccinating people at risk from the disease
   • Influenza
     • is a killer disease caused by a virus. people 65+ & those with respiratory tract condition particularly at risk
       • ~in attempts to avoid another WORLDWIDE epidemic (PANDEMIC), people at risk are immunised.