off label use; interchange of vaccine products; granulomatosis with polyangiitis; condition aggravated; this is a spontaneous report received from a contactable reporter(s) (consumer or other non hcp) from the regulatory agency. other case identifier(s): gb-mhra-vac-202202161041006770-4a6jx (ra), gb-mhra-adr 26609575 (ra). a 72 year-old male patient received bnt162b2 (comirnaty) (batch/lot number: unknown) as dose 3 (booster), single for covid-19 immunisation. relevant medical history included: "granulomatosis with polyangiitis" (ongoing), notes: for 30 years. the patient's concomitant medications were not reported. vaccination history included: covid-19 vaccine astrazeneca (dose 1; batch/lot number unknown), administration date: 03apr2021, for covid-19 vaccination, reaction(s): "acute kidney injury", "granulomatous polyangiitis", "condition aggravated"; covid-19 vaccine astrazeneca (dose 2; batch/lot number unknown), for covid-19 vaccination, reaction(s): "condition aggravated", "granulomatous polyangiitis". the following information was reported: off label use (hospitalization), outcome "unknown", described as "off label use"; interchange of vaccine products (hospitalization), outcome "unknown", described as "interchange of vaccine products"; granulomatosis with polyangiitis (hospitalization), outcome "unknown", described as "granulomatosis with polyangiitis"; condition aggravated (hospitalization), outcome "unknown", described as "condition aggravated". the patient underwent the following laboratory tests and procedures: blood test: result unknown. additional information: reaction got progressively worse during 2 astrazeneca jabs and a pfizer booster. it caused long standing condition of granulomatosis with polyangiitis (gpa) to flare. this reaction did not occur as a result of a mistake made in the administration of the vaccine. from patient medical history, blood tests have not shown a flare or alternatively an infection for the first time in medical history. consultants have assumed a flare. no follow-up attempts are possible; information about lot/batch number cannot be obtained. no further information is expected