How does that compare with other viral illnesses? Not downplaying, I've had bad episodes of flu that left me low on energy for weeks, want to see how that comp

How does that compare with other viral illnesses? Not downplaying, I've had bad episodes of flu that left me low on energy for weeks, want to see how that compares and if it's been looked into (I expect not given recency). My recovery from Covid in March was about on par with a bad flu, was late April until I felt good again and was back to normal on a physical level.