decreased ability to walk; balance had become affected; guillain barre syndrome; Initial information received on 05-Apr-2023 regarding an unsolicited valid serious case received from a healthcare professional.  This case involves a 17 month old female patient who experienced decreased ability to walk, balance had become affected and guillain barre syndrome after receiving vaccines PNEUMOCOCCAL VACCINE CONJ 7V (CRM197) (PREVNAR), MEASLES VACCINE LIVE (ENDERS-EDMONSTON), MUMPS VACCINE LIVE (JERYL LYNN), RUBELLA VACCINE LIVE (WISTAR RA 27/3), VARICELLA ZOSTER VACCINE LIVE (OKA/MERCK) (PROQUAD), INFLUENZA VACCINE (QUADRIVALENT) and DIPHTHERIA-15/TETANUS/5 AC PERTUSSIS VACCINE [DAPTACEL].  The patient's past medical history, medical treatment(s), vaccination(s) and family history were not provided.   On 20-Jan-2023, the patient received a  dose of suspect DIPHTHERIA-15/TETANUS/5 AC PERTUSSIS VACCINE Suspension for injection (strength: unknown) (lot number: C589399, expiry date: 21-Apr-2023) via unknown route in the left vastus lateralis, the patient received a  dose of suspect PROQUAD not produced by Sanofi Pasteur (lot number: w024969, expiry date: 05-Feb-2024) in the right vastus lateralis, the patient received a  dose of suspect PREVNAR not produced by Sanofi Pasteur (lot number: FX0079, expiry date: 30-Nov-2024)  in the left vastus lateralis and the patient received a  dose of suspect INFLUENZA VACCINE (QUADRIVALENT) produced by unknown manufacturer (strength, formulation, route: unknown) (lot number: ut775219, expiry date: 30-Apr-2023) in the right vastus lateralis for Prophylactic vaccination (Immunisation).  On 21-Jan-2023, the patient developed a serious event of guillain barre syndrome (guillain-barre syndrome) 1 day following the administration of DIPHTHERIA-15/TETANUS/5 AC PERTUSSIS VACCINE, INFLUENZA VACCINE (QUADRIVALENT), PROQUAD and PREVNAR. This event was assessed as medically significant. The patient was hospitalized for this event.  On an unknown date, the patient developed serious events of decreased ability to walk (gait disturbance), balance had become affected (balance disorder) (unknown latency) following the administration of DIPHTHERIA-15/TETANUS/5 AC PERTUSSIS VACCINE, INFLUENZA VACCINE (QUADRIVALENT), PROQUAD and PREVNAR. The patient was hospitalized for this event.  It was reported, required 5 days stay at medical center with IVIE treatment. Mom bought her to clinic on 02/02/2023 and stated that she had not walked normally since having the shots. At first, she thought her legs were just from the shots.   It is unknown if the patient experienced any additional symptoms/events. It is unknown if the patient had any medical history, concomitant disease or risk factor. It is unknown if there were lab data/results available.   Action taken with DIPHTHERIA, TETANUS AND ACELLULAR PERTUSSIS VACCINE (DAPTACEL), MEASLES VACCINE LIVE (ENDERS-EDMONSTON), MUMPS VACCINE LIVE (JERYL LYNN), RUBELLA VACCINE LIVE (WISTAR RA 27/3), VARICELLA ZOSTER VACCINE LIVE (OKA/MERCK) (PROQUAD), PNEUMOCOCCAL VACCINE CONJ 7V (CRM197) (PREVNAR) and QUADRIVALENT INFLUENZA VACCINE (INFLUENZA VACCINE (QUADRIVALENT)) was not applicable.  It was reported  the patient received a corrective treatment (IVIE treatment) for the events (guillain barre syndrome, decreased ability to walk, balance had become affected).  At time of reporting, the outcome was Recovering/Resolving for the event guillain barre syndrome, was Not Recovered / Not Resolved for rest of the events.; Sender's Comments: Sanofi company comment dated 11-Apr-2023: This case involves a 17 month old female patient who experienced decreased ability to walk, balance had become affected and guillain barre syndrome after receiving vaccines PNEUMOCOCCAL VACCINE CONJ 7V (CRM197) (PREVNAR), MEASLES VACCINE LIVE (ENDERS-EDMONSTON), MUMPS VACCINE LIVE (JERYL LYNN), RUBELLA VACCINE LIVE (WISTAR RA 27/3), VARICELLA ZOSTER VACCINE LIVE (OKA/MERCK) (PROQUAD), INFLUENZA VACCINE (QUADRIVALENT) and DIPHTHERIA-15/TETANUS/5 AC PERTUSSIS VACCINE [DAPTACEL]. Based upon the reported information, the role of vaccine cannot be assessed. Additional information regarding additional risk factor, family history, medical history, concomitant medication excluding other predisposing etiologies would be needed for complete assessment of the case.