Related Clues:
- Reason for a shot
- Reason to take a sick day
- Sick-day cause
- It may be avian
- Pandemic disease of 1918
- Bug with its own season
- Yuppie ___ (chronic fatigue syndrome)
- D-Day month
- Pandemic of 1918
- Bug that leaves you weak
- Bug with two homonyms
- Viral illness
- Blue ___ (cops' sickout)
- Solstice time
- Debilitating bug