CIE IGCSE Biology: 复习笔记:10.1.5 Vaccination: Extended

CIE IGCSE Biology: 复习笔记:10.1.5 Vaccination: Extended

Vaccination: Extended

  • Vaccinations give protection against specific diseases and boost the body’s defence against infection from pathogens without the need to be exposed to dangerous diseases that can lead to death
  • The level of protection in a population depends on the proportion of people vaccinated
  • Vaccines allow a dead or altered form of the disease-causing pathogen, which contains specific antigens, to be introduced into the body
  • In this weakened state, the pathogen cannot cause illness but can provoke an immune response
  • Lymphocytes produce complementary antibodies for the antigens
  • The antibodies target the antigen and attach themselves to it in order to create memory cells
  • The memory cells remain in the blood and will quickly respond to the antigen if it is encountered again in an infection by a ‘live’ pathogen
  • As memory cells have been produced, this immunity is long-lasting