Used an expired diluent; Used an expired diluent; slight headache; This is a spontaneous report received from contactable reporter(s) (Pharmacist) from medical information team and product quality group for a Regulatory Authority.  A 7 year-old male patient received bnt162b2 (BNT162B2), intramuscular, administered in deltoid left, administration date 12Feb2022 12:30 (Lot number: FL0007) at the age of 7 years as dose 2, 0.2 ml single for covid-19 immunisation; sodium chloride (SODIUM CHLORIDE), from 12Feb2022 (Batch/Lot number: unknown, Expiration Date: 01Feb2022) to 12Feb2022 at unk (diluent). The patient had no relevant medical history. There were no concomitant medications. Vaccination history included: Bnt162b2 (Dose: 1, Lot: FL0007, Expiry: Unknown, Anatomical site of injection: Left arm, Route of administration: Intramuscular), administration date: 22Jan2022, when the patient was 7 years old, for Covid-19 Immunization. The following information was reported: POOR QUALITY PRODUCT ADMINISTERED (non-serious), PRODUCT ADMINISTRATION ERROR (non-serious) all with onset 12Feb2022, outcome "unknown" and all described as "Used an expired diluent"; HEADACHE (non-serious) with onset Feb2022, outcome "unknown", described as "slight headache". The action taken for sodium chloride was unknown. No follow-up attempts are possible. No further information is expected.  Additional Information: The pharmacist reported that his concern was regarding the Pfizer Covid 19 orange cap. He reported that they administered doses of the vaccine where they used an expired diluent (10 days past the expiration date) and would like to ask for data regarding revaccination and if so would there be a need to wait for a longer amount of time prior to possible revaccination or subsequent dose of the vaccine.  Follow-up (14Feb2022): This is a follow up spontaneous report from a contactable pharmacist. This pharmacist reported for a patient that: Updated information include: Product complaint regarding Product: SODIUM CHLORIDE    The reporter spoke with Pfizer regarding dilution of the orange cap covid vaccine with 0.9% NaCl that was 11 days past expiration date. He thought the diluent was made by another manufacturer but it's labeled. The reporter wanted to know any guidance on what to do in this situation. NDC: 00409-4888-02. He reported that patients were administered this vaccine diluted with expired diluent. Caller stated he has already reported this to Pfizer and also to VEARS. He reported that no extension of expiration dating available on this product.  Follow-up (14Feb2022): This is a follow up spontaneous report from a Pfizer sponsored program [159558]. A contactable pharmacist reported for a male patient that: Updated information included : Added mailing address for slider#01, patient initials, DOB, gender, start date of BNT162B2, dose, units, lot no., route of administration, anatomical location, expiry date of sodium chloride, vaccine facility information, CEP id and classification. Dates for new bottle of diluent but it was expired, it was listed as 10 days after the manufacture date: (From 12Feb2022 To Unspecified). Reporter seriousness for new bottle of diluent but it was expired, it was listed as 10 days after the manufacture date: Not serious The pharmacist reported the inquiring about the administration of Covid-19 vaccine, the orange cap. He reported that it was diluted a couple days ago. It was mixed and reconstituted with the correct amount of sodium chloride, the diluent expired on 01Feb2022 and was administer on 12Feb2022. The reporter wanted to know if the individuals who received the vaccine need to be revaccinated, and if there is a certain amount of time they need to wait. The reporter clarified the vaccine was diluted with a fresh bottle of sodium chloride on Saturday 12Feb2022. It was a new bottle but it was expired, it was listed as 10 days after the manufacture date. It was a fresh new pop top sealed vial of sodium chloride. The pharmacist reported that a VAERS report has been filled out on the FDA website by the administering pharmacist. Then clarifies this is the first time he is reporting this event with Pfizer. The reporter wanted to see if the patients need to be revaccinated. The second dose the patients have already received. It has been 21 days, 23 days on Wednesday since the first dose. The diluent used to dilute was out of date. Parents were concerned because this is a child dose. and there was a high rate of myocarditis with large doses, wanting to know if they are putting the children at risk. The reporter was not at the pharmacy when this event occurred, he had never seen this individual and states he had no history to provide. The pharmacist reported that only thing to report is normal injection site reaction and ensures insures the are no worsening events. He reported that he did not know sodium chloride can expire, it is table salt and water. The only thing he would be concerned about is the viability of the vial, since the integrity of the vial has passed a certain date but not the contents. The pharmacist reported that there are no expiry date listed on these products, it is just 9 months from the manufacture date he thought, not an expiration date. Just the diluent was 10 days past the due. The vaccine was sold at 12:30 pm and was given so shortly after that. I was unknown if the patient received any other vaccine within 4 weeks.  Follow-Up (17Feb2022): Follow-up attempts are completed. No further information is expected.  Follow up (15Feb2022): This is a follow-up spontaneous report received from Pfizer product quality group providing investigation results. This report included: Product Quality Complaints / CITI / Complaint Contact. The reporter had a question about the diluent Pfizer covid-19 vaccine orange cap, it was mixed and reconstituted with the correct amount of sodium chloride. He reported that diluent had expired on 01Feb and it was administered and ministered on the 12th. He wanted to know if those individual that receive the diluent vaccine need to be re-vaccinated again and if so, is there any period time they are support to wait.  Follow up (01Mar2022): This is a follow up-spontaneous report received from the same contactable Pharmacist. This Pharmacist reported for the patient in response to HCP letter sent via follow-up letter which included that: Updated Information: New reporter added in slide#2, Historical vaccine notes field was added. New event 'slight headache' added. It was reported that specific relevant test for thromboembolic events with thrombocytopenia was Unknown. Type of Medical Error: Vaccine was mixed with expired diluent (saline) and administered. The pharmacist reported that they had multiple lots and expiration dates of saline mixed in their cabinet. That writer (the pharmacist who mixed the vaccine that day) did not check the expiration prior to mixing because he had seen unexpired saline in the cupboard dated out to 23Mar2022 and so he thought all of it was the same date. He checked in with the patient's guardian the day after the vaccine was administered and as of that day, the patient was doing well; he had a slight headache, but was otherwise well. Since then, several attempts to check in have been made and have been unsuccessful, so it is unknown how he is doing.  Follow-up attempts are completed. No further information is expected. Sender's Comments: Linked Report(s) : US-PFIZER INC-202200276742 same reporter/product/event, diff patients.