exhaustion/extreme exhaustion throughout day; second Covid diagnosis; second Covid diagnosis; febrile seizure; fever of 104; fell off of bed; Patient did not have appetite for breakfast; ill feeling; C-diff; This is a spontaneous report received from a contactable reporter(s) (Other Health Professional). A 5-year-old male patient received BNT162b2 (BNT162B2), in Dec2021 as dose 1, single (Batch/Lot number: unknown) at the age of 5 years for covid-19 immunisation. The patient's relevant medical history included: "pulmonary hypertension" (unspecified if ongoing), notes: Patient has history of pulmonary hypertension; "underdeveloped lungs" (unspecified if ongoing), notes: underdeveloped lungs; "oral aversion" (unspecified if ongoing), notes: oral aversion; "31 weeker" (unspecified if ongoing), notes: 31 weeker; "developmental delays" (unspecified if ongoing), notes: developmental delays; "Patient also had c-diff for 5 months" (unspecified if ongoing); "first Covid diagnosis" (unspecified if ongoing), notes: first Covid diagnosis.; "G-tube dependent" (unspecified if ongoing). The patient's concomitant medications were not reported. The following information was reported: FATIGUE (non-serious) with onset 02Jul2022, outcome "unknown", described as "exhaustion/extreme exhaustion throughout day"; DECREASED APPETITE (non-serious) with onset Jul2022, outcome "unknown", described as "Patient did not have appetite for breakfast"; FEBRILE CONVULSION (medically significant) with onset Jul2022, outcome "unknown", described as "febrile seizure"; FALL (non-serious) with onset Jul2022, outcome "unknown", described as "fell off of bed"; PYREXIA (non-serious) with onset Jul2022, outcome "unknown", described as "fever of 104"; MALAISE (non-serious) with onset Jul2022, outcome "unknown", described as "ill feeling"; DRUG INEFFECTIVE (medically significant), COVID-19 (medically significant) all with onset Jul2022, outcome "unknown" and all described as "second Covid diagnosis"; CLOSTRIDIUM DIFFICILE INFECTION (medically significant), outcome "unknown", described as "C-diff". The events "febrile seizure", "fever of 104" and "ill feeling" required emergency room visit. The patient underwent the following laboratory tests and procedures: Pyrexia: (Jul2022) 104, notes: Patient had a fever of 104; SARS-CoV-2 test: (Jul2022) Positive, notes: Patient was tested for Covid and came back positive. Additional information: During the night of 01Jul2022 & 02Jul2022, patient fell off of bed while sleeping. Patient's mother picked patient up and brought to bed. Patient woke up morning of 02Jul2022 with signs of exhaustion. Patient did not have appetite for breakfast. Patient is G-tube dependent and had a hard time tolerating morning and afternoon feed. Patient showed signs of extreme exhaustion throughout day. Mother took patient to urgent to get checked out. Urgent care determined fall was not cause ill feeling. Patient was sent home. At home patient had febrile seizure and was taken to ED (Emergency department). Patient was tested for Covid and came back positive. Patient had a fever of 104 when arrived at ED. This was patient's second Covid diagnosis since receiving first vaccine shot in Dec2021. Patient has not received second vaccine shot. Patient has history of pulmonary hypertension, underdeveloped lungs, oral aversion, 31 weeker, developmental delays. Patient also had C-diff for 5 months during vaccination and first Covid diagnosis. Patient had never had a seizure prior to this event.  The information on the batch/lot number for BNT162b2 has been requested and will be submitted if and when received.; Sender's Comments: Based on the currently available information the possibility of causal association between the serious  events and the suspect drug BNT162B2  cannot be ruled out. The case will be reassessed once new information is available. The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. 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