College of Science Lecture Series: Understanding Pandemics by Michael Worobey

Introduction

• Second installment of the College of Science lecture series.
• Thanks to sponsors like Arizona Daily Star, Raytheon, and others.
• Speaker: Michael Worobey, an evolutionary biologist specializing in viruses.

About Michael Worobey

• Grew up in British Columbia; Rhodes Scholar at Oxford.
• Professor of Ecology and Evolutionary Biology since 2003.
• Research focuses on how and when pandemics occur, especially HIV and influenza.
• Known for fieldwork in Africa and pioneering research techniques.

Influenza Overview

• Influenza is both a pandemic and seasonal virus.
• Two main lineages: H1N1 and H3N2.
• Annually infects 5-30% of the population, causing significant health and economic impacts.
• 1918 pandemic was unprecedented in severity and mortality.

1918 Influenza Pandemic

• Worst epidemic in US history, causing massive mortality.
• Young adults, 20-40 years old, were most affected, contrary to typical flu patterns.
• Decreased life expectancy in the US by 12 years; global death toll possibly up to 100 million.

Evolutionary Genomics

• Viruses like influenza are studied using evolutionary trees and genetic sequencing.
• Genomic analysis helps trace the history and origin of viruses.

The H and N Proteins

• H (hemagglutinin) allows the virus to enter cells.
• N (neuraminidase) enables new virus particles to escape host cells.
• Immune system produces antibodies targeting these proteins.

Antigenic Drift and Shift

• Flu viruses exhibit "Red Queen dynamics" due to constant immune evasion.
• Minor changes (antigenic drift) necessitate yearly vaccines.
• Major changes (antigenic shift) can lead to pandemics, as seen in 1918.

Historical Context and Research Discoveries

• 1918 virus had segments from birds and potentially horses.
• Historical accounts from 1872 suggest connections to a widespread equine flu epidemic.
• Research involves examining historical samples and using molecular clocks to date viral evolution.

Implications for Modern Pandemics

• Understanding past pandemics can help predict and manage future outbreaks.
• Current threats include H5N1, and the importance of targeted vaccination.
• Importance of protecting antibiotics as a resource against pandemics.

Vaccination and Immunity

• Flu vaccines target three strains: H3N2, H1N1, and influenza B.
• While effectiveness varies, vaccination remains a crucial preventive measure.

Closing Remarks

• Flu research continues to be vital for public health.
• Ongoing efforts to understand and mitigate the impact of influenza and other viruses.

Q&A Highlights:

• Discussion about the origins of H1N1 as a lab escape.
• Importance and effectiveness of current flu vaccines.
• Utilization of ferrets as a model for flu research due to their similar respiratory systems to humans.
• Understanding virus-host cell interactions.

Acknowledgments

• Thanks to collaborators and family for support during research.
• Exciting new findings and historical connections related to flu research were shared in this engaging lecture.