a patient who was administered two vaccines, unclear as to whether is was two flu vaccines or a flu vaccine and booster dose.; a patient who was administered two vaccines, unclear as to whether is was two flu vaccines or a flu vaccine and booster dose.; Patient has Soreness in one arm, since both vaccines were given in the same arm, caller thinks its the left arm; This is a spontaneous report from a contactable pharmacist. A female patient of an unspecified age received bnt162b2 (COMIRNATY, solution for injection), dose 3 via an unspecified route of administration, administered in Arm Left on 24Oct2021 (Batch/Lot number was not reported) as DOSE 3 (BOOSTER), SINGLE for covid-19 immunisation; influenza vaccine (INFLUENZA VIRUS VACCINE), via an unspecified route of administration from 24Oct2021 (Batch/Lot number was not reported) to 24Oct2021, at single for immunisation. The patient medical history and concomitant medications were not reported. Allergies were unknown. The patient previously received Dose 1 and dose 2 of covid-19 vaccine on an unknown date for covid-19 immunization (Primary Immunization series complete but unknown manufacturer).The patient previously was on antibiotic (unspecified). On 24Oct2021, the patient who was administered two vaccines, unclear as to whether it was two flu vaccines or a flu vaccine and booster dose (Booster and product use for unapproved combination), patient has soreness in one arm, since both vaccines were given in the same arm, caller thinks its the left arm. It was reported that patient was administered two vaccines, unclear as to whether it was two flu vaccines or a flu vaccine and booster dose. So, the pharmacist wants to ask is there any antibody test, certain lab value to determine administration and is there any harm in administering an additional booster dose. Pharmacist reported that they have a unique situation. Caller is a pharmacist at withheld, in their pharmacy they have many nurses and other pharmacist that are doing vaccination immunizations due to the large population. One Patient in particular thinks that instead of getting the Pfizer covid vaccine and Flu shot, she may have gotten 2 flu shots. Caller clarifies that this was a visit for the patient to get her 3rd booster shot. Caller states that what she has seen from her experience Flu shots cause more pain and local soreness. In this case both vaccines were given in the same arm so the patient responded yes, its sore, but it is unknown if she got double flu shots, or the flu shot and a booster. Caller states that because of patient privacy, there is a curtain at the time the patient receives the vaccines and so they cant determine what happened from the cameras. Caller asks if patient got 2 flu shots, or the covid vaccine would there be any specific antibody test, or a lab value that would determine percentage. What would be the harm in re-administering the booster. Patient has Soreness in one arm, since both vaccines were given in the same arm, caller thinks its the left arm. Caller states that she is hoping to resolve this for the patient, she is off work right now and wants to also give information to her partner. Caller was aware that the patient came in Sunday for the booster, so the second covid vaccine dose would have been at least 6 months since the second. This event took place Sunday 24Oct2021. Caller was probed for the name of the Flu Shot, caller states that she cant recall, they are rotating between Afluria, Flu Quad, Flu Zone, and Flucelvax. Caller states that she doesn't know if this patient came solely to her for the shot but she was generally healthy, she had a previous antibiotic on file. She did not receive the first and second dose of the covid vaccine doses at this pharmacy. The outcome of soreness in one arm was unknown.  The lot number for the vaccine, [BNT162B2], was not provided and will be requested during follow up.