Vaccination

• What is passive immunity?

  Immunity from antibodies introduced externally
• How are antibodies introduced in passive immunity?

  Through injection of pure antibodies
• What is a key characteristic of passive immunity?

  No memory cells are created
• What is active immunity?

  Immunity created by the body's own antibodies
• What are the two types of active immunity?

  Natural active and artificial active
• What is natural active immunity?

  Immunity from being infected by a pathogen
• What is artificial active immunity?

  Immunity gained through vaccination
• What is a vaccine?

  A weakened or dead form of a pathogen
• How do vaccines work?

  They activate B-cells to produce antibodies
• What do plasma cells do after vaccination?

  They produce antibodies for the pathogen
• What is the role of memory B-cells?

  They remain in blood for rapid response
• What happens during a secondary response?

  Rapid production of antibodies occurs
• What is the primary response?

  Initial exposure to a pathogen via vaccine
• How does herd immunity protect the population?

  Reduces pathogen spread among unvaccinated
• Why is herd immunity important?

  It protects vulnerable individuals unable to vaccinate
• What is antigen variability?

  Frequent mutations in pathogen DNA
• Why do some vaccines need to be updated?

  Pathogen mutations can change antigen shape
• Why is the flu vaccine updated annually?

  Influenza virus mutates rapidly
• What are the key differences between passive and active immunity?

  • Passive immunity:
  • Antibodies introduced externally
  • No memory cells created
  • Short-term protection
  • Active immunity:
  • Antibodies created by the body
  • Memory cells formed
  • Long-term protection
• What is the process of vaccination and its effects?

  1. Introduction of weakened/dead pathogen or antigens
  2. Activation of B-cells
  3. Clonal expansion and differentiation
  4. Production of plasma cells and memory B-cells
  5. Rapid antibody production upon re-exposure
• How does herd immunity function in a population?

  • Large proportion vaccinated
  • Reduces pathogen spread
  • Protects unvaccinated individuals
  • Prevents outbreaks
• What are the implications of antigen variability for vaccines?

  • Pathogen mutations can alter antigens
  • Memory B-cells may become ineffective
  • Need for updated vaccines (e.g., flu)