reconstituted with sterile water; Inappropriate dose of vaccine administered; 1mL was administered to the patient; This non-serious case was reported by a nurse via call center representative and described the occurrence of wrong solution used in drug reconstitution in a 16-year-old female patient who received Men ACWY-CRM NVS (Menveo) (batch number EK7DG, expiry date 31-DEC-2025) for prophylaxis. On 02-JAN-2025, the patient received Menveo. On 02-JAN-2025, an unknown time after receiving Menveo, the patient experienced wrong solution used in drug reconstitution (Verbatim: reconstituted with sterile water), inappropriate dose of vaccine administered (Verbatim: Inappropriate dose of vaccine administered) and overdose (Verbatim: 1mL was administered to the patient). The outcome of the wrong solution used in drug reconstitution, inappropriate dose of vaccine administered and overdose were unknown. It was unknown if the reporter considered the overdose to be related to Menveo. It was unknown if the company considered the overdose to be related to Menveo. Additional Information: GSK Receipt Date: 03-JAN-2025 The Healthcare Professional reported that Menveo 1 vial was reconstituted with sterile water from the MMR vaccine and 1ml was administered to the patient, which led to wrong solution used in drug reconstitution and inappropriate dose of vaccine administered.