Bladder infection; This is a spontaneous report from a contactable consumer(patient). A 88-years-old female patient received bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE, Formulation: solution for injection, Batch/Lot Number: EN6198) via an unspecified route of administration, administered in Arm Left on 06Mar2021 13:10 as dose 1, single for covid-19 immunization (age at vaccination 88-years-old). The patient's medical history included stent placement from 2014 and ongoing Verbatim: Stent between kidney and bladder. Concomitant medication(s) included warfarin sodium taken for international normalized ratio, start and stop date were not reported, cefalexin (KEFLEX [CEFALEXIN]), Coumadin taken for an unspecified indication, start and stop date were not reported. On an unspecified date the patient experienced bladder infection. Additional Context: This consumer reported having been administered her first dose of Pfizer-BioNTech COVID-19 Vaccine 06Mar2021. She has a bladder infection which she thinks she probably already had when she got the first dose of Pfizer-BioNTech COVID-19 Vaccine. She is taking antibiotic Cephalexin also known as Keflex for the bladder infection. She called to ask if it is ok to take the Cephalexin also known as Keflex or will it interfere with the second dose of Pfizer-BioNTech COVID-19 Vaccine she is scheduled to be administered on 27Mar2021. Bladder infection: Caller initially reported on call that she has an IUD and is taking Keflex to get rid of the bacteria. Clarified with caller what IUD stood for, such as intrauterine device, caller reported no, not intrauterine device, what she meant to say was bladder infection; and clarified that name of antibiotic from pharmacy bottle of product itself as Cephalexin also known as Keflex, Lot/NDC/Expiry: Unknown, product dispensed in pharmacy vial. Dose is 1-500mg capsule twice daily for 10 days. She has been taking for 3 days at time of this report. She probably already had the bladder infection when she got the first dose of Pfizer-BioNTech COVID-19 Vaccine. Bladder infection is not unusual for her because she has had a stent between her kidney and bladder for 7 years now; and every 3 months since then she has the stent removed and replaced-she has had the stent removed and replaced 32 times so far. She is prone to bladder and urinary tract infections because of having the stent for years and having the stent removed and replaced every 3 months. Anyone who has a stent for a long period is prone to infection. She has taken antibiotics several times as needed and the antibiotics have never bothered anything. Sometimes she has an infection, sometimes she does not. Her provider is Dr. Name at (Withheld). This time he recommended 3 days of antibiotic therapy, then changed it to 10 days because she has been on antibiotics for so many years that it takes more sometimes to get the infection down. On an unspecified date the patient underwent lab tests and procedures which included international normalized ratio: 2.8, white blood cell counts increased: white cells were up a little bit. Treatment was taken for the event. The outcome of the event was reported as recovering. No follow-up attempts are possible. No further information is expected.