A 28-year-old man with no prior vaccination history presents to a Delhi hospital for pre-travel immunization before a 3-month assignment in West Africa. He requires protection against yellow fever, and the clinic has just received a new shipment of yellow fever vaccine stored at 2–8°C. The vaccine vial shows a label indicating it was manufactured 18 months ago. The clinic's cold-chain monitor (a temperature indicator strip inside the vaccine carrier) shows that the shipment was exposed to 15°C for 6 hours during transit. What is the most appropriate next step?