his son received the whole vial of undiluted Pfizer BioNTech Covid-19 for his 2nd dose; his son received the whole vial of undiluted Pfizer BioNTech Covid-19 for his 2nd dose; Flu vaccine was given on 25Sep2021.; Flu vaccine was given on 25Sep2021.; Headache; He has a bull's eye redness on right hand; His arm is very heavy; He also feels drained out with weakness and tiredness; He also feels drained out with weakness and tiredness; This is a spontaneous report from a Pfizer sponsored program. A contactable nurse reported for his son that a 15-year-old male patient received BNT162B2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE, Batch/Lot Number: 301308A), via an unspecified route of administration, administered in arm right on 25Sep2021 16:30 (at the age of 15-year-old) as dose 2, single for COVID-19 immunisation. Medical history included he had had asthma since he was little. He was born premature and got respiratory syncytial virus infection (RSV). He was in the hospital for a week. He had been asthmatic pretty much his whole life. He had allergy testing where he received six pricks. He acted weird to that. He was allergic to everything they did there. The wheals were humungous. The nurse clarified that his son had not had an allergic reaction to a vaccine. Concomitant vaccine included influenza vaccine administered in left arm taken for immunization on 25Sep2021. Concomitant medications included salbutamol (ALBUTEROL) taken for asthma (the patient used it at night or whenever he felt a little tight. Used it daily, either in the middle of night or morning. Usually once a day). The patient was taking montelukast sodium (generic SINGULAIR) but now he was doing allergy shots. Trying to transition him to the allergy shots to decrease his hypersensitivity. His son didn't take other medications. The primary care doctor said to start him on Pepcid. The reporter gave him one of those. He may have to continue that moving forward. The reporter clarified his son was on generic Singulair. He didn't have the product with him. He can't remember the name, but it started with an M. The patient previously received first dose of BNT162B2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE, Batch/Lot Number: 301308A), on 04Sep2021 (at the age of 15-year-old) as single dose for COVID-19 immunization. The reporter stated that they received a call from (Pharmacy) that his son received the whole vial of undiluted Pfizer BioNTech Covid-19 for his 2nd dose on 25Sep2021. They called his son's primary care doctor this morning who called the CDC and the doctor's office called this morning to follow up and see how his son was doing. The reporter considered it was medically significant because they didn't know the long term effects. Right now they were on pins and needles. The reporter stated his son was having a headache and his arm was very heavy in Sep2021. He had a bull's eye redness about the size of a 50 cent piece on right arm. He received injection in right arm. He also felt drained out with weakness and tiredness in Sep2021. The patient had been alternating Tylenol (extra strength, 500mg, expiry: Feb2023, lot: 1DV1469) and Ibuprofen (lot: P141244, expiry: Jan2023, brand: HEB, Strength: 200mg) for the headaches. The reporter gave the anti-inflammatory, Motrin, and then Tylenol. The headaches had been unbearable. He became normal after taking Tylenol or Ibuprofen, or Motrin. When it wears off his son tells him. He was taking Motrin twice a day and Tylenol twice a day as needed for headache. The reporter kept his son under three grams of Tylenol daily (His son took two at a time) or the patient took 600mg of ibuprofen on full stomach. The outcome of the events was unknown.; Sender's Comments: Based on the temporal relation, the association between the events of headache, erythema, limb discomfort, asthenia and fatigue and the suspect product of BNT162B2 cannot be completely ruled out. These events were consequential to overdose and product preparation error. 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.