Inflammation; off label use; Booster; Both knees began to ache and turn stiff/Limited to knees, but it became very painful; Both knees began to ache and turn stiff; Can hardly stand up; His knees became puffy, pink, swollen, and warm; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP). The reporter is the patient.  A 68-year-old male patient received BNT162b2 (BNT162B2), on 03Mar2022 as dose 4 (booster), single (Lot number: FJ6369) at the age of 68 years, in left arm for covid-19 immunisation. The patient's relevant medical history included: "meniscus trim", start date: Jan2022 (unspecified if ongoing), notes: meniscus trim; "Blood pressure" (ongoing). Concomitant medication(s) included: TOPROL XL taken for blood pressure abnormal (ongoing); LIPITOR (ongoing); SPIRONOLACTONE AND HYDROCHLOROTHIAZIDE. Vaccination history included: BNT162b2 (Dose: 1, Lot: EN5318), administration date: 24Jan2021, when the patient was 67-year-old, for COVID-19 immunization, reaction(s): "Both knees began to ache and turn stiff", "Both knees began to ache and turn stiff", "Can hardly stand up", "His knees became puffy, pink, swollen, and warm"; BNT162b2 (Dose: 2, Lot: EN6198), administration date: 22Feb2021, when the patient was 67-year-old, for COVID-19 immunization, reaction(s): "Both knees began to ache and turn stiff", "Both knees began to ache and turn stiff", "Can hardly stand up", "His knees became puffy, pink, swollen, and warm"; BNT162b2 (Dose: 3, Lot: ER8737), administration date: 27Sep2021, when the patient was 68-year-old, for COVID-19 immunization, reaction(s): "Both knees began to ache and turn stiff", "Both knees began to ache and turn stiff", "Can hardly stand up", "His knees became puffy, pink, swollen, and warm"; Flu shot (He gets a Flu shot every year).  The following information was reported: IMMUNISATION (non-serious) with onset 03Mar2022, outcome "unknown", described as "Booster"; OFF LABEL USE (non-serious) with onset 03Mar2022, outcome "unknown"; JOINT STIFFNESS (non-serious) with onset Mar2022, outcome "not recovered", described as "Both knees began to ache and turn stiff"; ARTHRALGIA (non-serious) with onset Mar2022, outcome "not recovered", described as "Both knees began to ache and turn stiff/Limited to knees, but it became very painful"; DYSSTASIA (non-serious) with onset Mar2022, outcome "not recovered", described as "Can hardly stand up"; JOINT SWELLING (non-serious) with onset Mar2022, outcome "not recovered", described as "His knees became puffy, pink, swollen, and warm"; INFLAMMATION (non-serious), outcome "recovering". The events "both knees began to ache and turn stiff/limited to knees, but it became very painful", "both knees began to ache and turn stiff", "can hardly stand up", "his knees became puffy, pink, swollen, and warm" and "inflammation" required physician office visit. Relevant laboratory tests and procedures are available in the appropriate section. Therapeutic measures were taken as a result of arthralgia, joint stiffness, inflammation.  Additional information: He wanted to report an adverse reaction to Pfizer COVID vaccine. where he got the vaccine. He went for an annual physical and asked for the second booster. It was his fourth shot. First 3 minimal if any reaction. The fourth shot, two days or three days after, both knees began to ache and turn stiff. It got hard from sitting to standing position. He can hardly stand up. It has continued since. Became puffy, pink, swollen, warm knees. No fever. Limited to knees, but it became very painful. He was a pickle ball player before, but he could hardly move around after. He went to his orthopedic doctor and primary. Nobody knows what to do. All they do is manage pain. Ortho doctor after 9 months did X rays and compared it to his x rays a year ago. The space between his knee has disintegrated on the inside edge. It is markedly worse to where it is now bone on bone on the inside edge. Seems to be inflammatory reaction. All they do is Pain meds or Diclofenac Gel (NSAID that he puts on knee joint) It seems to work to reduce pain. Atleast to the point where he can walk. The doctor basically told him they will manage pain until he can't, and then he will have to get his knees replaced. Outcome: in the last 3 weeks he heard things online from a doctor who put out a detox protocol, and to take ivermectin and NAC (amino acid) and something else. He changed what he eats to just salads. Trying to be non inflammatory. The last couple of weeks inflammation has seem to go down. until them has been the same. He gets a Flu shot every year. He did get his Flu shot in late Sep2022 and had a reaction to it. It was elevated heart rate and rapid breathing; it was the stronger dose. NDC/lot/expiration: Unknown. He considers himself fairly healthy. It didn't seem like osteoarthritis. He did have a meniscus trim in Jan2022. His Knees were in great shape with no arthritis or roughness then. There was a little reduction from spacing from inside to outside, but minimal. From Jan2022 and Jan2023, the space is now gone. They tested him for Rheumatoid arthritis factor it was negative. He has been on the same medications for a long time. No other vaccinations within four weeks prior to the first administration date of the suspect vaccine.   No follow-up attempts are possible. No further information is expected.; Sender's Comments: Linked Report(s) : US-PFIZER INC-202300053967 Same patient/vaccine/event, different dose;US-PFIZER INC-202300053968 Same patient/vaccine/event, different dose;US-PFIZER INC-202300053969 Same patient/vaccine/event, different dose;