Unraveling the 1918 Flu Pandemic: Key Questions for Scientists

Despite extensive research, key mysteries of the 1918 H1N1 pandemic remain:

• Origin: Avian? Swine? Human adaptation? Exact zoonotic source unknown
• Rapid spread: Troop movements, crowding, and viral transmissibility drove global reach (500M infected)
• High lethality (50–100M deaths): Unique virulence factors (PB1-F2, HA, NA), cytokine storm, secondary bacterial pneumonia, and host factors (young adults disproportionately affected)
• Long-term sequelae: Neurological (encephalitis lethargica), cardiovascular, and socioeconomic impacts across generations

Ongoing studies (viral resurrection, phylogenetics, immunology) inform pandemic preparedness.