serious epilepsy; A PHASE3, MULTICENTER, RANDOMIZED, DOUBLE-BLIND STUDY TO EVALUATE THE INTERCHANGEABILITY OF V114, A 15-VALENT PNEUMOCOCCAL CONJUGATE VACCINE, AND PCV13 WITH RESPECT TO SAFETY, TOLERABILITY, AND IMMUNOGENICITY IN HEALTHY INFANTS(PNEU-DIRECTION)  This is a non-Pfizer sponsored interventional study report for the following literature source(s).  An infant patient received pneumococcal 13-val conj vac (dipht CRM197 protein) (PREVNAR 13), as dose 2, single (Batch/Lot number: unknown) at the age of 4 months for immunisation. The patient's relevant medical history was not reported. Concomitant medication(s) included: ROTATEQ oral taken for immunisation; PENTACEL intramuscular taken for immunisation. Vaccination history included: Prevnar 13 (Dose 1, SIngle), when the patient was 2 months old, for immunization; Rotateq (Dose 1, oral), when the patient was 2 months old, for immunization; Pentacel (Dose 1, intramuscular), when the patient was 2 months old, for immunization; Recombivaxhb, when the patient was 2 months old, for immunization. The following information was reported: EPILEPSY (medically significant), 1 day after the suspect product(s) administration, outcome "unknown", described as "serious epilepsy". The patient underwent the following laboratory tests and procedures: Body temperature: Unknwon results. Clinical course: The patient had a serious AE (epilepsy on day 1 following PCV13 dose 2) considered to be related to the study intervention and subsequently discontinued the study prior to receiving dose3.  The investigator considered there was a reasonable possibility that the event "serious epilepsy" was related to pneumococcal 13-val conj vac (dipht CRM197 protein).; Sender's Comments: Epilepsy is unlisted in Data Sheet of PREVNAR 13 and related per Company assessment.  Based on the information, Company considers there is a reasonable possibility that epilepsy is related to PREVNAR 13.  Seizure is recognized as a known ADR of PREVNAR 13 in children; the neurological complication might lower the threshold for epilepsy attack thus trigger serious epilepsy episode which occurred just one day following the vaccination.  Underlying genetic predisposition, exogenous etiologies such as infective agents, and young age with high vulnerability to neurological events could also be considered as confounders.    Pfizer's safety database reviewed for cases reporting PNEUMOCOCCAL 13-VAL or blinded therapy through 30JUN2023 for AEs encoding PTs of Epilepsy;Febrile convulsion;Generalised tonic-clonic seizure;Partial seizures;Seizure;Seizure cluster;Seizure like phenomena. Results of Database Review for Epilepsy: 1 serious clinical trial (SCT) cases (0 attributed to therapy) and 167 non-CT cases.  Results for Febrile convulsion: 60 SCT cases (3 attributed to therapy) and 761 non-CT cases.  Results for Generalised tonic-clonic seizure: 1 SCT cases (0 attributed to therapy) and 116 non-CT cases.  Results for Partial seizures: 3 SCT cases (0 attributed to therapy) and 41 non-CT cases.  Results for Seizure: 28 SCT cases (2 attributed to therapy) and 857 non-CT cases.  Results for Seizure cluster: 0 SCT cases (0 attributed to therapy) and 3 non-CT cases.  Results for Seizure like phenomena: 1 SCT cases (0 attributed to therapy) and 8 non-CT cases.  Impact of the report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including review and analysis of aggregate data for AEs. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to regulatory authorities, Ethics Committees, and Investigators, as appropriate.