pneumonia; hep a; act-hib was administered to a patient but the diluent was expired; Initial information was received on 12-Apr-2023 regarding an unsolicited valid serious case received from a other health professional.  This case involves 1 years old female patient who experienced pneumonia, hep a and act-hib was administered to a patient but the diluent was expired while receiving vaccine hib (prp/t) vaccine [ACT-HIB].  The patient's past medical history, medical treatment(s), vaccination(s) and family history were not provided.   Concomitant medications included DIPHTHERIA VACCINE TOXOID, PERTUSSIS VACCINE ACELLULAR, TETANUS VACCINE TOXOID (DTAP VACCINE) for Immunisation.  On 21-Jul-2021 she also received a 1 dose of 0.5ml  of the same vaccine lot UJ667AB , via intramuscular route in Right thigh .  On 21-Sep-2021 she also received a 2 dose of 0.5ml  of the same vaccine lot UJ667AB via intramuscular route in Right thigh for Immunization.  On 23-Dec-2021 she also received a 3 dose of 0.5ml  of the same vaccine lot UJ667AB via intramuscular route in Right thigh for Immunization. On 12-Apr-2023, the patient received a 4 dose of of 0.5ml  suspect hib (prp/t) vaccine lot UJ667AB, 07apr-2023,  DILUENT LOT U7261AA EXP 07APR2023 via intramuscular route in Right thigh for Immunization .   On 12-Apr-2023 the patient developed a non-serious event of act-hib was administered to a patient but the diluent was expired (expired product administered) 1 year 8 months 22 days following the administration of hib (prp/t) vaccine. On an unknown date the patient developed a serious event of pneumonia (unknown latency) following the administration of hib (prp/t) vaccine. This event was assessed as medically significant. On an unknown date the patient developed a non-serious event of hep a (hepatitis a) (unknown latency) following the administration of hib (prp/t) vaccine.  Action taken with haemophilus type b (hib) vaccine (ACT-HIB) was not applicable.  It was not reported if the patient received a corrective treatment for the events (pneumonia, hep a, act-hib was administered to a patient but the diluent was expired).  At time of reporting, the outcome was Unknown for the event pneumonia, was Unknown for the event hep a and was Unknown for the event act-hib was administered to a patient but the diluent was expired.   This suspected adverse reaction report is submitted and classified as a medication error solely and exclusively to ensure the marketing authorization holder's compliance with the requirements set out in the Directive 2001/83/EC and Module VI of the Good Pharmacovigilance Practices. The classification as a medical error is in no way intended, nor should it be interpreted or construed as an allegation or claim made by the marketing authorization holder that any third party has contributed to or is to be held liable for the occurrence of this medication error. Seriousness criteria; Sender's Comments: Sanofi company comment dated 17-Apr-2023: This case involves 1 years old female patient who experienced pneumonia, hep a and act-hib was administered to a patient but the diluent was expired while receiving vaccine hib (prp/t) vaccine [ACT-HIB]. Based on information provided, the causal role of company suspect cannot be excluded. Case will be re-evaluated post further update on information regarding underlying disease, risk precipitating factor, other concomitant medication, past medical history and patient lifestyle which will aid a comprehensive assessment of this case. Based upon the reported information, the role of the suspect  cannot be assessed.