Myocarditis/had another virus that went to her heart; trouble remembering; incredible fatigue; could sleep around the clock; brain fog; This is a spontaneous report from a contactable nurse (Patient). An 80-years-old female patient received the second dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE, lot number: EL9265), intramuscular at Right Deltoid from on 16Feb2021 11:00 at single dose for covid-19 immunisation. Medical history included stomach was burning, heartburn, low thyroid, myocarditis and was hospitalized a year ago, Milroy's disease, and low potassium, heart disorder and Back disorder. Concomitant medications included bumetanide (BUMEX) Has been taking for about 40 years for Milroy's disease, rosuvastatin calcium (CRESTOR) from Jan2020 for Myocarditis, levothyroxine Has been taking for 40 years for low thyroid, tramadol Started about 10-12 years ago for back, metoprolol from Jan2020 for heart, omeprazole (PROTONIX) Started taking about 8 years ago for stomach was burning and heartburn, potassium Has taken for 40-50 years for low potassium, vitamin B12, vitamin D3 and baby aspirin 81mg, all were ongoing. The patient received first dose of BNT162B2 (lot number: EL8982) on an unknown date for covid-19 immunization and she got a really sore arm. The patient experienced Myocarditis/had another virus that went to her heart on an unspecified date, brain fog on 17Feb2021, trouble remembering on an unspecified date, incredible fatigue on 17Feb2021, could sleep around the clock on 17Feb2021. The clinical course as following: injection was on 16Feb2021. She has had incredible fatigue. She was asking how long is the fatigue going to last. She knows it is a side effect but she could sleep around the clock. She stated she goes to bed at 6PM if not before then and gets up at around 8AM and by 9AM she could go back to bed. She is sorry she got the shot because she is miserable. She mentioned she has been reading up on the vaccine and it said "you might have fatigue for a day or two". Her fatigue has now been 8 days. She thought "how long is this going to go on".  Patient reported that with the first shot she got a really sore arm. Stated she thinks the person giving the injection put the darn thing through her bone. She thought it was to be expected, but it feels like the person who administered the vaccine was a poor shot giver. She provides the first Covid Vaccine Lot number: EL8982. With the second shot her arm did not get sore at all. The only thing she's having was the fatigue, she can hardly walk past her bed without wanting to get back in it. She tries to get up to shower and fix her hair and be motivated and she's been fighting the fatigue all day to not get back in bed. When probed for the seriousness criteria of the fatigue, the caller explains she doesn't think it's that significant. She thought it will go away. However, she was just coming out of myocarditis. She was just in the hospital for myocarditis and they did a heart cath and she has no plugged arteries, nothing. They couldn't find anything other than she had another virus that went to her heart. She had another virus a year ago January. She wonders if COVID was out there then, because she had never been so sick with the flu. She kind of diagnosed her problem and it was like a wave over her body. She also had a terrible irregular pulse. When she went to the hospital the next morning, her cardiac enzymes were 4.5 times more than normal, her troponin was out of sight. She doesn't think that would have a bearing because she should be coming out of that myocarditis because of the medication the doctor put her on. She doesn't know if that would complicate it, too. Her heart doctor said a lot of people have myocarditis, especially athletes, but they are young and fall over dead. 90% of the time, its myocarditis because you don't know you have it.  She reports she's getting a foggy brain. Her son asked her who her dentist was because she had a root canal and she couldn't think of the dentist's name. She thinks her son threw that in because her son knew that she wouldn't be able to remember. She's not confused. It's just difficult to get the word out, but if she waits a couple minutes, she has the answer. She is also getting old, too. She lives by herself; she has no stimulation and she thinks that is significant to her circumstances. She thinks it's a problem with the COVID-19 injection. Caller explains she had blood work very recently about 2 weeks ago. She just looked at lab reports and everything was okay except one of the vitamins was a tiny bit high (she can't remember what the vitamin was), but nothing she was worried about. It could have been a Potassium was a little high, but she is not worried about that. Her main question is how long the fatigue last, she thought for only 1-2 days. She mentions she took her temperature every morning and its always like 97 something and it's never wavered. The outcome of the events brain fog, incredible fatigue, and could sleep around the clock was not recovered and the outcome of the other events was unknown.; Sender's Comments: Based on the information provided, viral myocarditis is most likely due to a viral infection in this patient with cardiovascular co-morbidities and is not related to suspect product. 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. This case will be reassessed upon receipt of additional information.