types of immunity

• Compare passive and active immunity?

  Passive immunity doesn't involve memory cells and antibodies aren't replaced when broken down (short-term).

  Passive immunity is immediate, antibodies come from an external source and no direct contact with antigen is necessary.

  Whereas in active immunity memory cells are produced (long-term)

  There is a time lag.

  Lymphocytes produce antibodies.

  Requires direct contact with antigen.
• Active v passive immunity?

  Passive immunity is acquired through the transfer of antibodies from another source (not long-term), while active immunity is acquired through the production of antibodies by the body's own immune system.
• An example of passive natural immunity?

  Antibodies in breast milk / across placenta
• An example of passive artificial immunity?


  anti-venom, needle stick injections
• An example of active natural immunity?

  humoral response to infection
• An example of active artificial immunity?

  Vaccination
• Active natural immunity?

  When you become immune after catching a disease.

  E.g if you have measles as a child, you shouldn't e able to catch it later in life- antibodies.
• What is active artificial immunity?

  This is when you become immune after you've been given a vaccination containing attenuated pathogens / antigens.
• What is passive natural immunity?

  This is when a baby becomes immune due to the antibodies it receives from its mother, through the placenta and in breast milk.
• What is passive artificial immunity?

  This is when you become immune after being injected with antibodies from someone else.

  E.g if you contract tetanus you can be injected with antibodies against the tetanus toxin, collected from blood donations.
• Passive immunity?

  The type of immunity you get from being given antibodies made by a different organism (your immune system doesn't produce any antibodies of its own)
• Active immunity?

  This is the type of immunity you get when your immune system makes its own antibodies after being stimulated by an antigen.
• How do new strains of a disease arise?

  Mutation

  (or variation)
• Why is vaccination active immunity?

  antibodies are produced by the person being vaccinated

  activation of lymphocytes of the person being vaccinated

  specific memory cells remain in the person being vaccinated
• How do vaccines work?

  1 a vaccine is produced that is a safe form of an antigen

  2) a small amount of a vaccine is injected into the blood of the individual to be vaccinated

  3) antigen presentation occurs

  4) clonal expansion, plasma cells are produced which secrete antibodies

  5) memory cells produced from clonal expansion of B cells, secondary immune response
• herd immunity: fewer people can catch the virus

  vaccinated individuals cannot spread the virus, thus the number of people with the virus are reduced
• Why is it not possible to protect against the different pathogens of MMR (measles, mumps & rubella) using only one vaccine?

  different pathogens have different antigens

  antigens have a specific shape

  the shape of the antibody must be complementary to the antigen

  thus a different antibody is needed for each pathogen