On the simultaneous inference of susceptibility distributions and intervention effects from epidemic curves
This paper addresses the challenge of simultaneously inferring individual susceptibility heterogeneity and intervention effects from epidemic curves. We propose an identifiable joint inversion framework based on an extended SEIR model that incorporates individual-level variation in susceptibility and exposure. Using maximum likelihood estimation, we innovatively fit multiple epidemic datasets jointly to estimate shared parameters—thereby resolving the fundamental identifiability limitations inherent in conventional variable-susceptibility models. To our knowledge, this is the first rigorous validation of parameter inferability for such models. Our results demonstrate that, under realistic data quality conditions, the framework accurately recovers the true susceptibility distribution and key intervention-effect parameters. The method substantially improves the reliability of epidemic forecasting and the precision of public health policy evaluation. By establishing both theoretical guarantees and empirical evidence, it provides a foundation for integrating population heterogeneity into data-driven public health decision-making.