<jats:title>Abstract</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>This study aimed to estimate the age-stratified and overall morbidity and mortality rates of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection based on an analysis of the pervasive SARS-CoV-2 epidemic in Qatar, a country with &lt;9% of the population being ≥50 years of age.</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>Infection disease outcomes were investigated using a Bayesian approach applied to an age-structured mathematical model describing SARS-CoV-2 transmission and disease progression in the population. The model was fitted to infection and disease time-series and age-stratified data. Two separate criteria for classifying morbidity were used: one based on actual recorded hospital admission (acute-care or intensive-care-unit hospitalization) and one based on clinical presentation as per World Health Organization classification of disease severity or criticality.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>All outcomes showed very strong age dependence, with low values for those &lt;50 years of age, but rapidly growing rates for those ≥50 years of age. The strong age dependence was particularly pronounced for infection criticality rate and infection fatality rate. Infection acute-care and intensive-care-unit bed hospitalization rates were estimated at 13.10 (95% CI: 12.82-13.24) and 1.60 (95% CI: 1.58-1.61) per 1,000 infections, respectively. Infection severity and criticality rates were estimated at 3.06 (95% CI: 3.01-3.10) and 0.68 (95% CI: 0.67-0.68) per 1,000 infections, respectively. Infection fatality rate was estimated at 1.85 (95% CI: 1.74-1.95) per 10,000 infections.</jats:p></jats:sec><jats:sec><jats:title>Conclusions</jats:title><jats:p>SARS-CoV-2 severity and fatality in Qatar was not high and demonstrated a very strong age dependence with &lt;4 infections in every 1,000 being severe or critical and &lt;2 in every 10,000 being fatal. Epidemic expansion in nations with young populations may lead to lower disease burden than previously thought.</jats:p></jats:sec>