Purdue University Pharmacy (PUP) 575 Stadium Mall Dr. Walk-in flu shots. Flu shots are available now at PUP. Walk-ins are welcome between 8:30 a.m. and 5 p.m., Monday through Friday. PUP is using a Flucelvax Quadrivalent Pre-filled Syringe. It is a preservative-free, egg-free, latex-free product. Additional flu shot options..