Fig 5. Observed trends in COVID-19 compared to influenza-negative influenza-like illness (ILI) in high-income countries.

Trends in reported COVID-19 cases (blue line) and influenza-negative ILI cases (black line) during 2020. The vertical dotted black line indicates the week of the first COVID-19 case, the vertical dashed line indicates the week of the first COVID-19 peak, and the red diamond indicates the first detected influenza-negative ILI outlier in 2020.