dose 1: 17Apr2021/ dose 2: 04May2021 = 18 days; inclusive myositis, IBM; legs felt more heavy/ having trouble lifting left leg/ Heavy leg syndrome; Myositis; Muscle enzymes normally are 200, hers shot up to 7500 and then they got it down to 4500; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP) from medical information team.  A 58-year-old female patient received BNT162b2 (BNT162B2), on 04May2021 as dose 2, single (Batch/Lot number: unknown) at the age of 57 years, in left arm for covid-19 immunisation. The patient's relevant medical history included: "Rheumatoid arthritis", start date: 2017 (ongoing). There were no concomitant medications. Vaccination history included: BNT162b2 (dose 1, administered in the left arm, Batch/Lot number: unknown), administration date: 17Apr2021, when the patient was 57-year-old, for COVID-19 immunization, reaction(s): "Legs felt funny/ Heavy leg syndrome", "Myositis", "didn't feel good". The following information was reported: MUSCLE ENZYME INCREASED (non-serious) with onset 2021, outcome "not recovered", described as "Muscle enzymes normally are 200, hers shot up to 7500 and then they got it down to 4500"; MYOSITIS (non-serious) with onset 2021, outcome "not recovered"; INCLUSION BODY MYOSITIS (medically significant) with onset 2021, outcome "unknown", described as "inclusive myositis, IBM"; LIMB DISCOMFORT (non-serious) with onset 2021, outcome "unknown", described as "legs felt more heavy/ having trouble lifting left leg/ Heavy leg syndrome"; INAPPROPRIATE SCHEDULE OF PRODUCT ADMINISTRATION (non-serious) with onset 04May2022, outcome "unknown", described as "dose 1: 17Apr2021/ dose 2: 04May2021 = 18 days". The patient underwent the following laboratory tests and procedures: Muscle enzyme: (2021) 7500, notes: normal: 200; (unspecified date) 4500, notes: normal: 200. Therapeutic measures were taken as a result of inclusion body myositis, limb discomfort, myositis, muscle enzyme increased. The clinical course was as follows: The reporter was calling about Pfizer COVID-19 vaccine to report an adverse reaction that his wife (patient) has had. She had the first COVID-19 vaccine and her leg felt funny. They didn't know the vaccine was causing it. She got second shot and legs felt more heavy. Then she got the booster shot and her legs were really heavy and they diagnosed her with heavy leg syndrome. Now, she was diagnosed with myositis. Muscle enzymes normally are 200, hers shot up to 7500 and then they got it down to 4500. She was going to rheumatologist who said she could never get another COVID-19 vaccine and to report it. Her legs got worse a day or two after second shot and that is when she went to general practitioner. She was having trouble lifting left leg. The general practitioner said she had heavy leg syndrome. She didn't feel good after first vaccine. After the second vaccine she was sick for a week. Then when she got booster she was laid out for a week again. She has never recovered after the booster. She couldn't walk up stairs anymore. She has to use a cane if on the floor or has to have someone help her get up. The rheumatologist does video conferences with doctors around the country. The rheumatologist said that half of the doctors were saying that they believe it is from the vaccine and the other half were on the fence. The next step is to go for a biopsy because none of the medicines were working. The rheumatologist didn't think it is curable. Starting to lean towards inclusive myositis, IBM. She was so active before the vaccines with walking and swimming. Now she couldn't leave the house. She used to enjoy the garden and couldn't go outside now.  The information on the batch/lot number for BNT162b2 has been requested and will be submitted if and when received.; Sender's Comments: Linked Report(s) : US-PFIZER INC-202201225949 same reporter/patient/suspect drug, different dose number/event;US-PFIZER INC-202201227276 same reporter/patient/suspect drug, different dose number/event;