Antigenic variation

• How does antigenic variation affect the immune response?

  The immune system must start from scratch
• Why does antigenic variation complicate vaccine development?

  New antigens require new vaccines each year
• What is antigenic variation?

  Pathogens change their antigens to evade immunity
• What are the implications of antigenic variation for flu vaccinations?

  • Influenza vaccine changes annually
  • Different strains circulate each year
  • Memory cells from one strain do not recognize others
  • New vaccines are developed for effective prevention
• Which pathogens are examples of those that show antigenic variation?

  HIV and the influenza virus
• Why do memory cells from vaccination with one flu strain fail to recognize other strains?

  Strains have different antigens and are distinct
• How does the annual change in the influenza vaccine reflect antigenic variation?

  It adapts to new circulating virus strains
• What is the role of governments and health authorities regarding flu vaccines?

  They implement vaccination programs with new vaccines
• What happens to the influenza virus antigens over time?

  They change regularly, forming new strains
• What is the significance of serotypes in relation to antigenic variation?

  They refer to pathogens with antigen variation
• Why does it take time to eliminate an infection caused by antigenic variation?

  The immune system needs to recognize new antigens
• How does antigenic variation impact public health strategies?

  It necessitates ongoing vaccine updates and education
• What is the relationship between antigenic variation and the effectiveness of flu vaccines?

  Effectiveness varies with changing virus strains