she will bruise in the drop of a hat; This is a spontaneous report from a contactable registered nurse (the patient). A 53-year-old female patient received the second dose of BNT162B2 (PFIZER-BIONTECH COVID-19 MRNA VACCINE, lot number EL3249), via an unspecified route of administration in the left deltoid on 13Jan2021 13:00 (at the age of 53-years-old) as a single dose for COVID-19 immunization. The patient's medical history included: Von Willebrand's disease: diagnosed from when she was 8-years-old- when she was baby she went in for cleft palate repair and they gave her aspirin and she almost didn't survive, when she went for tooth removal the dentist suggested she get tested; mitral valve prolapse: diagnosed from when she was 13 or 15-years-old; Treacher-Collins' syndrome: diagnosed at birth. The patient had no family history. There were no concomitant medications. The patient previously received the first dose of BNT162B2 (PFIZER-BIONTECH COVID-19 MRNA VACCINE, lot number EK5730), via an unspecified route of administration in the right deltoid on 22Dec2020 13:00 (at the age of 52-years-old) as a single dose for COVID-19 immunization. The patient did not receive any other vaccines within four weeks prior to the vaccination. No other vaccine was administered on the same date as the Pfizer vaccine. The patient had a history of Von Willebrand disease, but since getting her second vaccine dose on 13Jan2021, she has noticed that she has been bruising more easily, since Mar2021. This has continued for over a month now. It had never been an issue before. She didn't bruise easily, but since she got the vaccine, she noticed she will bruise in the drop of a hat (Mar2021). In the last couple of months, she has had bruises that she didn't have any idea where they came from. She noticed more bruising a month or a month half ago on the inside of the right forearm. Then probably two or three weeks ago, she noticed bruises on both her right and left thighs. Then yesterday, she went to give blood from the right anti cube, and she got a bruise from that. The bruises on her thighs were still there. She had her physical yesterday with her primary healthcare professional who stated he had seen a couple of people with this side effect. She asked whether she should get a booster third dose when it becomes available. The patient considered the event bruise in the drop of a hat to be medically significant. The outcome of the event was not recovered.; Sender's Comments: Based on the current available information and the plausible drug-event temporal association, a possible contributory role of the suspect product BNT162B2 to the development of event Bruise cannot be excluded. The medical history of Von Willebrand's disease may provide a plausible alternative explanation for the event.  The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to Regulatory Authorities, Ethics Committees and Investigators, as appropriate.