Lecture Notes on Flu Research

Introduction

• Scientific inquiries build upon each other, forming a vast repository of human knowledge.
• Focus on understanding how the flu virus travels globally and identifying the origin of outbreaks.

Study Insights

• Researcher: Trevor Bedford and team.
• Objective: Trace the travel habits and origins of flu viruses.

Flu Outbreaks Origin

• Most flu strains originate from South China, India, and Southeast Asia.
• Genetic tracking using flu RNA samples creates a comprehensive flu family tree.
  • Visualization: Represented with paper and pipe cleaners.
  • Each circle represents a flu sample.
  • Largest study of flu evolution; 10,000 samples.

Differences Between Flu A and Flu B

• Flu A
  • Includes strain H3N2, the most common and deadly seasonal flu.
  • Evolves quickly, leading to short-lived immunity.
  • High mutation rate; prevalent re-infections every 5-10 years.
• Flu B
  • Evolves slowly, primarily infects children.
  • Immunity developed in childhood lasts 15-20 years.

Flu Travel Patterns

• Flu B
  • Can remain in one location for several years.
  • Example: A variant stayed in Southeast Asia for six years.
• H3N2
  • Travels rapidly globally.
  • It often migrates from Southeast Asia, dominating in North America.

Factors Influencing Flu Spread

• H3N2: Spreads rapidly due to air travel.
  • Adults frequently travel, facilitating virus spread.
• Flu B: Primarily affects children who travel less, slowing its spread.

Implications for Vaccine Development

• Better vaccines can be developed by understanding flu migration and evolution.
• Regional tailoring of Flu B vaccines.
• Identify dominant strains for H3N2 to improve vaccine efficacy.

Conclusion

• Each study enhances our understanding of global flu dynamics.
  • Provides insights into vaccine strain selection to combat seasonal flu.
• Continual research leads to a deeper and more interesting view of the world.