he plunger would not depress; prefilled syringe that would not depress; lightheadedness; patient was stuck twice / considered a possible overdose; This case was reported by a pharmacist via call center representative and described the occurrence of light headedness in a 10-year-old female patient who received Flu Seasonal QIV Dresden (Fluarix Tetra 2020-2021 season) (batch number 373H3, expiry date 30th June 2021) for prophylaxis. This case was associated with a product complaint.   Co-suspect products included flu seasonal qiv dresden pre-filled syringe device (Fluarix Tetra Pre-Filled Syringe Device) injection syringe for prophylaxis, Flu Seasonal QIV Dresden (Fluarix Tetra 2020-2021 season) (batch number 5D4H4, expiry date 30th June 2021) for prophylaxis and flu seasonal qiv dresden pre-filled syringe device (Fluarix Tetra Pre-Filled Syringe Device) injection syringe for prophylaxis.   On 1st December 2020, the patient received Fluarix Tetra 2020-2021 season (intramuscular), Fluarix Tetra Pre-Filled Syringe Device, Fluarix Tetra 2020-2021 season (intramuscular) and Fluarix Tetra Pre-Filled Syringe Device. On 1st December 2020, less than a day after receiving Fluarix Tetra 2020-2021 season, Fluarix Tetra Pre-Filled Syringe Device, Fluarix Tetra 2020-2021 season and Fluarix Tetra Pre-Filled Syringe Device, the patient experienced light headedness. On an unknown date, the patient experienced overdose, pharmaceutical product complaint and needle issue. On an unknown date, the outcome of the light headedness was recovered/resolved and the outcome of the overdose, pharmaceutical product complaint and needle issue were unknown.   The reporter considered the light headedness to be related to Fluarix Tetra 2020-2021 season, Fluarix Tetra Pre-Filled Syringe Device, Fluarix Tetra 2020-2021 season and Fluarix Tetra Pre-Filled Syringe Device.   This report is made by GSK without prejudice and does not imply any admission or liability for the incident or its consequences.  Additional details and Follow of information received from QA department were provided as follows: The reporter was a pharmacist. She reported that yesterday (1st December 2020) she was injecting Fluarix (to a female pediatric patient) and when trying to inject the prefilled syringe into the patient the plunger would not depress.  The reporter said it was difficult to tell but she does not think any medication came out.  The reporter also does not know if it could have been an issue with the needle or with the prefilled syringe.  The lot number of the prefilled syringe that would not depress was 373H3.  It was the last one out of the box of 10. FLU.QIV PRTC 10 CT FS US NH20.  Please credit for 1/10th of a box.  The prefilled syringe with needle attached was in the sharps container and therefore was not available for return.  No picture was taken. Pharmacist got a new prefilled syringe of Fluarix from a new box lot 5D4H4 and put a new needle on and was able to successfully inject the patient.  Filing as a related Adverse Event due to the fact that the patient was stuck twice and that if even a drop came out during the 1st injection that would be considered a possible overdose.  Both the 1st and 2nd injection were given intramuscularly in the left deltoid but not in the same exact spot on the deltoid.  The patient did experience some lightheadedness which did resolved.  Difficult to push plunger questions: the plunger eventually push or was unusable, not any blockages visible in the syringe body or barrel, no any abnormal particles observed in the vaccine, yes there was Luer Lok needle used. Summary of the QA statement were received as follows: A customer reported a complaint which falls within the following product technical complaint An investigation had been conducted, including review of the reported defect trends, the retained samples and our production records, which has demonstrated that the subject batch was produced in compliance with the applicable procedures and met all required specifications. Additionally, no deviation which could be related to the reported complaint has been identified and all of applicable verifications confirmed the conformity of the batch to specifications. Given the outcome of its investigation, GSK Biologicals considers the complaint that was the object of this report as unsubstantiated.