Pandemics & Society Webinar 12 March, “Patterns of age-specific mortality during influenza pandemics: evidence for immune imprinting?”.
For the sixth Pandemics & Society Seminar of our Spring 2026 series we are pleased to welcome Nathaniel Darling (University of Cambridge). The seminar will be held on Thursday, 12 March at the normal time (16:00 CEST). More information about our speaker and the presentation is below. You can sign up for email notifications about the seminar series, including the Zoom details, here.
About the talk:
This talk presents work conducted jointly with Henrik Salje. The 1918 influenza pandemic was marked by unusually high mortality among young adults. The immune-imprinting hypothesis explains this pattern as a cohort effect arising from antigenic mismatch: individuals first exposed in childhood to influenza strains dissimilar to the 1918 virus were less protected and therefore experienced higher mortality. We test this hypothesis by examining age-specific mortality patterns across the pandemics of 1918, 1957, 1968, and 2009. Using long-run, cause- and age-specific mortality data for a panel of countries, we estimate excess mortality for each age group and each pandemic year within a consistent framework, and reconstruct cohort-level measures of antigenic mismatch based on historical circulation. Initial results suggest that imprinting mismatch captures important elements of the observed age patterns, yet the fit remains incomplete, pointing to additional mechanisms beyond imprinting that shaped pandemic mortality.
About the speaker:
Nathaniel Darling is a PhD student based in the Cambridge Group for the History of Population and Social Structure (CAMPOP). His research seeks to model the infectious disease dynamics shaping historical mortality patterns.