Vaccines

• Ethical issues with vaccines

  • Tested on animals
  • Humans in chemical trials put themselves at rusk because they think they are immune
  • Fears of side effects
  • Difficult decisions on who gets the vaccine first gif there is a new disease
• Why vaccines might not fully eliminate diseases

  • Fails to induce immunity in some people (immunodeficiency)
  • Slow primary response
  • pathogens mutate (Different strains)
  • objections to vaccinations
• Herd immunity - when a large proportion of a population is vaccinated, so that the disease cannot spread
• Active immunity

  • Body makes antibodies after being exposed to an antigen
  • long term immunity because memory cells produced
  • Natural active immunity - become immune after catching the disease
  • Artificial active immunity - become immune after being given a vaccination
• Passive immunity

  • Body is given antibodies by a different organism
  • Short term no immune response involved and no memory cells produced
  • Natural passive immunity - Baby gets antibodies through placenta and breast milk
  • Artificial immunity - injected with antibodies
• Problems with passive immunity

  • Protection is temporary and only lasts a few months after birth