Vaccines, Disease and Monoclonal Antibodies

• What are the two main types of immunity?

  Active and passive
• Active immunity is acquired when an antigen enters the body, triggering a specific immune response, where antibodies are produced.
• Active immunity is naturally acquired through exposure to microbes or artificially acquired through vaccinations
• How is active immunity naturally acquired?

  Exposure to pathogens
• How is active immunity artificially acquired?

  Vaccination
• In both naturally acquired and artificially acquired active immunity, the immune system is stimulated to produce memory cells, along with plasma cells, giving the individual long-term immunity
• Active immunity results in the individual developing long term immunity
• In active immunity, during the primary response to a pathogen or vaccine, the antibody concentration in the blood takes one to two weeks to increase.
• If the body is invaded by the same pathogen again, or by the pathogen that the person was vaccinated against, the secondary response will occur
• What is the secondary response?

  The re-introduction of pathogens to an individual after a vaccination or primary infection
• In the secondary response, the antibody concentration in the blood takes a much shorter period of time to increase and is higher than after the vaccination or first infection.
• Passive immunity is acquired without an immune response, as antibodies are not produced by the infected person.
• How is passive immunity acquired?

  Without an immune response, as the antibodies are not produced by the infected person
• In passive immunity, as the individuals immune system has not been activated, there are no memory cells that can produce antibodies in a secondary response, therefore, if a person is reinfected, they would need another infusion of antibodies
• Why may passive immunity occur?

  Depending on the disease an individual is infected with, they may not have time to actively acquire the immunity (active immunity), so passive immunity occurs either artificially or naturally
• What are the two types of active immunity?

  Artificial and natural
• What are the two types of passive immunity?

  Artificial and natural
• How is artificial passive immunity acquired?

  When people are given an injection or transfusion of antibodies
• How is passive immunity acquired for people with tetanus?

  Tetanus is an antitoxin, the antibodies were collected from people whose immune system has been triggered by a vaccination to produce tetanus antibodies
• How is natural passive immunity acquired?

  • Foetuses receive antibodies across the placenta from their mothers
  • Babies receive the initial breast milk from mother, which delivers a certain isotype of antibody
• In active immunity, antibodies are produced by the body
• In passive immunity, antibodies are not produced by the body.
• In active immunity the antibodies appear in the blood in 1-2 weeks
• In passive immunity, the antibodies appear in the blood immediately
• In active immunity, memory cells are present
• In passive immunity, memory cells are not present
• What is a vaccine?

  A suspension of antigens that are intentionally put into the body to induce artificial active immunity, a specific immune response where antibodies are released by plasma cells
• A vaccine is a suspension of antigens that are intentionally put into the body to induce artificial active immunity
• What are the two main types of vaccines?

  Live attenuated and inactivated
• What are live attenuated vaccines?

  Vaccines that contain the whole pathogens that have been ‘weakened’
• Live attenuated vaccines contain whole pathogens that have been weakened, they therefore multiply slowly, allowing for the body to recognise the antigens and trigger the primary immune response.
• Live attenuated vaccines tend to produce a stronger and longer lasting immune response
• What is the disadvantage of live attenuated vaccines?

  They can be unsuitable for people with weak immune systems as the pathogen may divide before sufficient antibodies can be produced
• What is an example of a live attenuated vaccine?

  MMR
• What is an inactivated vaccine?

  A vaccine that contains whole pathogens that have been killed or small parts of the pathogens, such as proteins, sugars or harmless forms of toxins
• The advantage of inactivated vaccines is that they are suitable for everyone including those who have weak immune systems
• What is a disadvantage of inactivated vaccines?

  They do not trigger a strong or long lasting immune response like live attenuated vaccines, and therefore, repeated doses and/or booster doses are often required
• Inactivated vaccines often require booster or repeated doses
• Why doe inactivated pathogens need boosters?

  They do not trigger a long lasting or strong immune response
• Live attenuated vaccines dont often require booster doses as they have a strong and long lasting immune response