Maladministration of Engerix-B after the expiration date; This non-serious case was reported by a other health professional via call center representative and described the occurrence of expired vaccine used in a 3-month-old male patient who received HBV (Engerix B Junior) (batch number ZP72S, expiry date 15-DEC-2024) for prophylaxis. On 03-JAN-2025, the patient received Engerix B Junior. On 03-JAN-2025, an unknown time after receiving Engerix B Junior, the patient experienced expired vaccine used (Verbatim: Maladministration of Engerix-B after the expiration date). The outcome of the expired vaccine used was unknown. This report is made by GSK without prejudice and does not imply any admission or liability for the incident or its consequences. Additional Information: GSK Receipt Date: 03-JAN-2025 Certified medical assistant called to report the maladministration of an expired dose of an Engerix-B 10 micrograms dose to a patient just a few days after the expiration date, which led to an expired vaccine used. The reporter needs an advice on what to do with the patient. The vaccine administration facility was the same as primary reporter.