2C.3 - 2C.4 Immunity, Vaccines, and Antigenic variation

• why does antigenic variation make creating vaccinations difficult?

  • antigens change depending on the varient of the disease so it is difficult to make a vaccine as new ones need to be made regularly. • health authorities and the government choose the most sustainable vaccine to be used.
• how does antigenic variation affect humans?

  the different antigens presented require new antibodies to be formed ( memory cells from the original strain are not complimentary to the new variant). the immune system has to start again with the primary response which takes time, causing illness.
• what is antigenic variation?

  mutations in the genes of pathogens cause different antigens to be formed, resulting in new strains of disease.
• what are the ethical concerns for vaccinations?

  • they are tested on animals. • some contain animal based substances. • the human stage is testing can be risky.• side effects. • priority of who gets vaccinated first is unfair.
• what is the disadvantage with vaccinations being ingested orally and nasally?

  • it can be broken down by enzymes in the gut.• it can sometimes be too large to absorb into the blood.
• how can vaccinations be taken?

  • orally.• nasally. • injection.
• what is heard immunity?

  when there are high levels of vaccinated people/natural immunity that prevent the disease from spreading and harming unvaccinated people.
• why do we get vaccinations?

  they cause the body to produce memory cells (provide immunity) without the pathogen causing disease.
• what do vaccinations contain?

  antigens, either alone or on the surface of a weakened/inactive pathogen.
• which immunity only offers short term protection?

  passive. memory cells are not made and antibodies are quickly broken down.
• which immunity offers long term protection and how?

  active. memory cells are made.
• which immunity doesn't produce memory cells?


  passive.
• which immunity provides immediate protection?

  passive.
• which immunity requires exposure to antigens?

  active.
• what are the differences between active and passive immunity?

  active. • requires exposure to antigens.• protection is not immediate.• memory cells are produced.• protection is long term. passive.• doesn't require exposure to antigens.• protection is not immediate. • no memory cells are produced.• protection is short term.
• what is artificial active immunity?

  immunity after being injected with antibodies produced outside the organism.
• what is natural passive immunity?

  when a baby becomes immune due to antibodies received through breast milk and the placenta.
• what is passive immunity?

  immunity by receiving antibodies made by other organisms.
• what are the two types of passive immunity?

  natural and artificial.
• what are the two types of active immunity?

  natural and artificial.
• what is artificial active immunity?

  when you become immune after reviewing a vaccination containing a harmless dose of antigen.
• what is natural active immunity?

  when you become immune after catching a disease.
• what is active immunity?

  when the body makes its own antibodies due to stimulation from an antigen.
• what are the two types of immunity?

  active and passive.
• How do vaccines work

  Vaccines contain antigens from a the pathogen - this is either dead or inactive

  phagocytosis occurs and the macrophage presents the antigens on its surface

  this stimulates helper T cells with complimentary receptors to bind to the antigens and then divide by mitosis

  these clones can differentiate into cytoxic T cells which release perforin that destroy infected cells, or more helper T cells

  when B lymphocytes collide with activated helper T cells, it stimulates them to divide by mitosis and the produce can differentiate into plasma cells or memory cells