After her second COVID-19 Vaccine, she had a really bad flare up of rheumatoid arthritis; This is a spontaneous report received via pharmacy. A contactable consumer (patient herself). A 61-year-old female patient received BNT162B2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE; Solution for injection, Lot Number: EW0162/Batch number was not reported), dose 2 via an unspecified route of administration, administered in arm left on 13Apr2021 (at the age of 60-years-old) as 2nd dose, single dose for covid-19 immunisation. Medical history included rheumatoid arthritis from 2003 and ongoing (she also has a pre-existing condition of arthritis). The patient's concomitant medications were not reported. The patient did not receive any other vaccines within four weeks prior to the vaccination. The patient previously received BNT162B2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE; Solution for injection, Lot Number: EW0162/Batch number was not reported) dose 1 via an unspecified route of administration, administered in arm left on 23Mar2021 (at the age of 60-years-old) as 1st dose, single dose for covid-19 immunisation and xeljanz xr for rheumatoid arthritis (reported she continued to take her Xeljanz XR 11mg while she took the Prednisone 5mg tablets, providing the Xeljanz XR 11mg). The reporter stared that for after patient second COVID-19 Vaccine, she had a really bad flare up of rheumatoid arthritis. The reporter wanted to know if her rheumatoid arthritis would be a contraindication in getting the booster third dose of the Pfizer BioNTech Covid-19 Vaccine. Warm transfer from Pharmacy, with a patient who takes Xeljanz XR 11mg. The patient stated she got both doses of the Pfizer (COVID-19) Vaccine, and after her second (COVID-19) Vaccine, she had a really bad flare up of rheumatoid arthritis. The patient stated her doctor put her on Prednisone for 2 weeks. Reviewed and clarified the transferring agent's report details with the caller. Reported she had received her second COVID-19 Vaccine dose right before her 61st birthday. She said she went to her rheumatologist, and her rheumatologist told her she should report her side effects to Pfizer. She said she already reported her COVID-19 Vaccine side effects on V-Safe. She said she had to get her second Pfizer BioNTech COVID-19 Vaccine at the University of (withheld) because the store she received her first Pfizer BioNTech COVID-19 Vaccine at said she missed her second vaccine appointment time. Rheumatoid Arthritis Flare Up Treatment: Stated her rheumatologist prescribed 1 Prednisone 5mg tablet, once a day, for 2 weeks. She said she saw her rheumatologist on 17May2021. She said she completed her Prednisone 5mg prescription, and the Prednisone 5mg tablets were dispensed in a pharmacy bottle, and she didn't have the Prednisone 5mg NDC, Lot, and Expiration Date. Reported she was feeling better now, but wanted to report her Pfizer BioNTech COVID-19 Vaccine side effects to Pfizer, so she could help other people with rheumatoid arthritis. Reported she continued to take her Xeljanz XR 11mg while she took the Prednisone 5mg tablets, providing the Xeljanz XR 11mg: (NDC Number: 0069-0501-30, LOT Number: DJ2906, Expiration Date: 31May2022). No relevant tests were performed. Therapeutic measures were taken as a result of after her second covid-19 vaccine, she had a really bad flare up of rheumatoid arthritis (rheumatoid arthritis). The reporter stated the event result in Physician Office visit. The outcome of the event was resolving.