Diarrhea; Felt burning all over her abdomen and through her urine; Felt burning all over her abdomen and through her urine; Felt unwell before even getting the vaccine but its worse; Felt unwell before even getting the vaccine but its worse; Dizziness/it is worse now; Vision problems/it is worse now; Blood clot; has to do with retina; This is a spontaneous report from a contactable nurse (patient). An 85-year-old female patient received BNT162B2 (COMIRNATY Solution for injection), via an unspecified route of administration, in the right deltoid (also reported as right shoulder), on 29Sep2021 (lot number: EWO168), at the age of 84 years old, as dose 1, single, for COVID-19 immunisation. Relevant medical history included blood pressure high, Breast cancer, spinal stenosis, felt unwell before even getting the vaccine, allergies (allergic to everything and needs to be careful), vision problems, dizziness all from unknown dates, not reported if ongoing or not; had a radiation with breast cancer in 2011, and burning reaction and thyroid surgery/took her thyroid out on unspecified dates; and ongoing mastocytosis from an unknown date. Concomitant medications included vitamin D3 and vitamin C (ascorbic acid) for unknown indications, and paracetamol (TYLENOL) for spinal stenosis, and an unspecified blood pressure medication, start and stop dates not reported. The patient is a retired registered nurse who got her first dose of the Pfizer Biontech COVID19 (Comirnaty) vaccine on 29Sep2021. She had no problem at all. She went in positively because she wants the vaccine. She was bound and determined to not have a problem. She was due for second vaccine on 20Oct2021 was thinking of putting it on 10Nov2021. On 19Oct2021, she got diarrhea. It was runny every time she went to the bathroom. More would come out. She didn't become incontinent. It stopped and she didn't have it through the night. Then the burning started. She was peeing every hour. Then she thought it was a urine infection but it wasn't. She was up all night with burning all over in the abdomen and through the urine. She has had this reaction when she had radiation when she had breast cancer. She reacted to radiation that way. She called hospital where she was going to get the vaccine and they said not to come in. She was able to see her physician's assistant that same day at 11AM. Tested urine and it was clear. Urine was sent for culture and it was not the urine. She has had burning since. She has not gone back to the doctor because she thinks it will work itself out. She has not done anything else or eaten anything different. The only time she has had that burning was when she reacted to medication. Once when she had antibiotic and it only lasted a couple of days. The same thing with radiation. She is having health issues otherwise. She will have MRI of brain on 29Oct2021 because she was having vision problems, and dizziness. The patient clarified that vision problems, dizziness, and stuff like that were before the vaccine. That was already there, but it is worse now. It is fluctuating. She saw her primary care, eye doctor, and a retinal specialist. It has to do with retina and blood clot that she had after thyroid surgery. They could operate down the line, but at present time with symptoms it is not a safe thing to do. They did say to definitely continue to have MRI of the brain. She had a carotid study and that was clear. Her concern is she has Mastocytosis. She takes "antihistamine 1 and 2" (as reported). The patient clarified that she takes Pepcid 20mg twice a day and the loratadine 10mg in the morning. She hasn't called back her doctor's office. She doesn't know what to do. She figured it would work its way out. She thought the best thing is to check with Pfizer and see what they say. This is not one of the side effect listed except diarrhea and tiredness that is on the paper. The patient has read that the second dose can lead to myocarditis and wanted to know if the burning is a fore runner or indicative of the problem she might have with the second dose. If she continues with the shot she may have problem that way. Is there anything more the doctor can do? What does Pfizer say? She is already on antihistamine is there more than can be done? The patient stated that the events were not life threatening and not disabling. It was annoying. She wouldn't go to the hospital for that. She is a nurse. She tends to let things go. It will be alright. She plays or talks herself out of it. She ignores it. She is ignoring it, but it is not going away. It does quiet down sometimes. It is worse in the morning and during the night. She attributes that to being on the antihistamine. She doesn't take the antihistamine until 9AM and by afternoon it doesn't goes away but subsides. She attributes that to the antihistamine helping it. That gives her a sign it is a reaction since the antihistamine helps it. The outcome of the events was unknown. The outcome of the events was unknown. Causality of events was reported as "She would suspect that it is because she has had nothing else enter her body or be in her body at this time."; Sender's Comments: Based on the Limited information in the case, a contributory effect of the vaccine BNT162B2 to the reported events clot blood and retinal disordercannot be ruled out. 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.