Influenza infection of humans has occurred throughout history. The virus is constantly changing and evolving, which is why we need a new vaccine every year. But what about pandemic strains? They happen when genetic reassortment generates a new virus. Such an event occurred in 1918 when an estimated 50 million people worldwide were killed by an unusual flu, one that frighteningly devastated otherwise healthy 20- to 30-year-olds.

Elizabeth Anderson is out to find out why that happened, hypothesizing that that generation’s immune systems were primed with a distinct influenza subtype during their 1890s childhood, one that left them ill-equipped to fight this new strain decades later. But it is unknown what strains were circulating in the 1890s.

In collaboration with the Pathology Department at the University of Pennsylvania, Anderson is collecting 19th-century lung specimens to characterize these mystery strains and to determine the impacts of immune imprinting on disease fatality rates. This talk will detail how past exposures to influenza viruses shape the host response and how this might have affected the 1918 influenza pandemic.