Related Clues:

• Cold kin
• Sick-day excuse
• Shot's target?
• Tough bug
• Possible work force reducer
• Month for dads and grads
• Fever cause
• WHO concern
• Wintertime woe
• Solstice month
• Major WWI killer
• Cause of many a sick day
• Wintertime ailment
• Reason to stay in bed
• ___ vaccine