A 6-month-old male infant from rural Madhya Pradesh presents to the primary health centre with his mother for routine immunisation. The child is healthy with no contraindications. On reviewing the immunisation card, the health worker notes that the infant received BCG and OPV-0 at birth, and DPT-1, IPV-1, and Hepatitis B-1 at 6 weeks. The mother asks which vaccine should be given today as per the Universal Immunisation Programme (UIP) schedule. What is the most appropriate next vaccine to be administered?