swelling of fingers; stiff fingers; wrist pain/pain in elbow; positive rheumatoid factors; this is a spontaneous report received from a contactable reporter (consumer) from the regulatory agency (ra). the reporter is the patient. other case identifier(s): gb-mhra-vac-202202271504299330-rrvkh (ra), gb-mhra-adr 26657176 (ra). a 31 year-old female patient (not pregnant) received bnt162b2, administration date 21aug2021 (lot number: ff3319) as dose number unknown, single for covid-19 immunisation. the patient's relevant medical history and concomitant medications were not reported. patient last menstrual period date was 02feb2022. patient was not currently breastfeeding. the following information was reported: arthralgia (medically significant) with onset 07sep2021, outcome "not recovered", described as "wrist pain/pain in elbow"; peripheral swelling (medically significant) with onset 25oct2021, outcome "not recovered", described as "swelling of fingers"; musculoskeletal stiffness (medically significant) with onset 25oct2021, outcome "not recovered", described as "stiff fingers"; rheumatoid factor positive (medically significant) with onset 2021, outcome "unknown", described as "positive rheumatoid factors". the patient experienced wrist pain on 07sep2021 and pain in elbow on 02nov2021 respective, and both with outcome not recovered. the events "wrist pain/pain in elbow", "swelling of fingers", "stiff fingers" and "positive rheumatoid factors" were evaluated at the physician office visit. general practitioner (gp) referred her to rheumatology specialist and confirmed positive rheumatoid factors. the patient underwent the following laboratory tests and procedures: rheumatoid factor: (2021) positive. treatment received was cortisone shot on 25nov2021. therapeutic measures were taken as a result of arthralgia, peripheral swelling, musculoskeletal stiffness, rheumatoid factor positive. the reporter did not think this reaction occurred as a result of a mistake made in the administration of the vaccine. no follow-up attempts are possible. no further information is expected