DEERFIELD, Ill.--(BUSINESS WIRE)--Flu shots are now available daily with no appointment necessary at all Walgreens pharmacies and Healthcare Clinics nationwide, and Duane Reade pharmacies in New York, the company announced today. Flu shots are offered on a walk-in basis during all pharmacy and clinic hours while an immunizing health professional is on duty, including evenings, overnights at 24-hour pharmacy locations, weekends and holidays1. Age restrictions vary by state at Walgreens pharmacie