No additional AE; HCP called to report a 11-year-old patient was administered PROQUAD, when she was only due for Varicella vaccine. Inquiring about the validity of the Varicella and potential side effects of additional MMR II. See request cases, 02741163 and 0271190.; This spontaneous report was received from Other Health Professional (Medical Assistant) and refers to an 11-year-old female patient. The patient’s pertinent medical history, concurrent conditions, previous drug reactions or allergies and concomitant medications were not reported. On 22-JAN-2025, the patient was vaccinated with measles, mumps, rubella, and varicella (oka-merck) virus vaccine live (rHA)(PROQUAD) injection, lot #X026597, expiration date: 11-MAY-2025, administered for prophylaxis (strength, dose, route of administration, and anatomical site of injection were not provided). The patient was only due for the varicella vaccine, but the combination vaccine (PROQUAD) was administered instead (wrong product administered). Additionally, the patient was vaccinated with sterile diluent (MERCK STERILE DILUENT) solution for injection/infusion (strength, dose description, lot #, expiry date, route of administration, and indication were not provided). No additional adverse events were reported (no adverse event). No additional information was available.