{Reference Type}: Journal Article {Title}: Uncertainty and error in SARS-CoV-2 epidemiological parameters inferred from population-level epidemic models. {Author}: Whittaker DG;Herrera-Reyes AD;Hendrix M;Owen MR;Band LR;Mirams GR;Bolton KJ;Preston SP; {Journal}: J Theor Biol {Volume}: 558 {Issue}: 0 {Year}: 02 2023 7 {Factor}: 2.405 {DOI}: 10.1016/j.jtbi.2022.111337 {Abstract}: During the SARS-CoV-2 pandemic, epidemic models have been central to policy-making. Public health responses have been shaped by model-based projections and inferences, especially related to the impact of various non-pharmaceutical interventions. Accompanying this has been increased scrutiny over model performance, model assumptions, and the way that uncertainty is incorporated and presented. Here we consider a population-level model, focusing on how distributions representing host infectiousness and the infection-to-death times are modelled, and particularly on the impact of inferred epidemic characteristics if these distributions are mis-specified. We introduce an SIR-type model with the infected population structured by 'infected age', i.e. the number of days since first being infected, a formulation that enables distributions to be incorporated that are consistent with clinical data. We show that inference based on simpler models without infected age, which implicitly mis-specify these distributions, leads to substantial errors in inferred quantities relevant to policy-making, such as the reproduction number and the impact of interventions. We consider uncertainty quantification via a Bayesian approach, implementing this for both synthetic and real data focusing on UK data in the period 15 Feb-14 Jul 2020, and emphasising circumstances where it is misleading to neglect uncertainty. This manuscript was submitted as part of a theme issue on "Modelling COVID-19 and Preparedness for Future Pandemics".