It just about wiped out cognitive function; shallow breathing; panting; Not being able to get around; he shrunk from 6 foot getting older; exhausted; Hungover feeling/he felt like in his eye sockets and in his neck and everywhere that there was something in him, some unfamiliar sensation; The caller stated a few days ago he had an intense dizziness after he got the first dose of the vaccine.; little anxiety; change in heart rhythm/change in his pulse rate/His normal is usually 60 but in this case it was 56 to 60; slight headache; This is a spontaneous report from a contactable consumer and a consumer via Pfizer-sponsored program Pfizer First Connect. A 75-year-old male patient received bnt162b2 (PFIZER-BIONTECH COVID-19 VACCINE; Lot Number: EZ5138), via an unspecified route of administration in the left arm on 29Jan2021 12:01 (age at time of vaccination:  75 years) at first single dose for COVID-19 immunization; Vaccination Facility: community clinic. Medical history included bone marrow donor from an unknown date and unknown if ongoing (about 20 years ago). There were no concomitant medications. The patient experienced the following events and outcomes: the caller stated a few days ago he had an intense dizziness after he got the first dose of the vaccine. on 01Feb2021 at 11:30 with outcome of recovering, it just about wiped out cognitive function on an unspecified date with outcome of unknown, slight headache on 29Jan2021 with outcome of unknown, little anxiety on 01Feb2021 with outcome of recovered on 02Feb2021, shallow breathing on an unspecified date with outcome of unknown, change in heart rhythm/change in his pulse rate/his normal is usually 60 but in this case it was 56 to 60 on 01Feb2021 with outcome of recovered on 02Feb2021, exhausted on 02Feb2021 with outcome of recovering, panting on an unspecified date with outcome of unknown, hungover feeling/he felt like in his eye sockets and in his neck and everywhere that there was something in him, some unfamiliar sensation on 02Feb2021 with outcome of recovering, not being able to get around on an unspecified date with outcome of unknown, he shrunk from 6 foot getting older on an unspecified date with outcome of unknown; all of which were medically significant. The events did not require a visit to a physician office or emergency room (ER).  The patient did not receive any prior vaccinations within four weeks of the bnt162b2; and there were no additional vaccines administered on the same date of the Pfizer Suspect. The patient underwent lab tests and procedures which included blood pressure: good on an unspecified date, height: shrunk from 6 foot getting older on an unspecified date, heart rate: good on an unspecified date, pulse rate: 56 to 60 on an unspecified date.    The caller stated a few days ago he had an intense dizziness after he got the first dose of the vaccine. This was 72 hours after the shot. He had the shot around 12:01 last Friday (29Jan2021). Monday (01Feb2021), about the same time, he had a very very intense dizziness that came on suddenly (came on in about 30 seconds) and it was full blown and it lasted for pretty much 24 hours. It slightly lessened after 20 hours but it was a day before he could stand up. It was not gradual, he knew right then he was in trouble, he couldn't sit up or roll over. He stated he was in great health but if he was taking medication or had a heart condition he doesn't think he would be available for this conversation. It stressed him out and he didn't know he could go that far and come back. He stated it was comparable to cardiac arrest and was a life threatening experience. If other people may have this reaction (if intoxicated or on drugs) they may not survive it. It was very very severe and scary. He stated his reaction seems extreme to everybody he knows. It just about wiped out cognitive function. He stated around here it doesn't seem that people are having severe reactions. He knows a couple people getting the shot, one who drinks, one who had diabetes and he let them know about this.  Additional Context: The patient stated he wanted to report his experience and ask a question. The patient stated he received the first dose of the Pfizer COVID 19 vaccine on 29Jan2021 at 12:01 in the left arm. The patient did not use drugs or alcohol and did not have any medication and had good health. The patient's heart rate and blood pressure were good. The patient had a slight headache. Then 72 hours later on Monday at about 11:30 he started to get dizzy, suddenly, and it was very intense. The patient took about 12 steps and recognized it and got to the bed. By the time he got there he knew he was in trouble, he had little anxiety and noticed a change in heart rhythm. The dizziness was very intense and intensified when he went to bed and continued.  Tuesday morning it lightened a bit and then around 11:30 on Tuesday it withdrew; exactly 72 hours from the vaccination. The patient felt okay now, except he was kind of exhausted and had a hungover feeling, not totally clear but he was walking around.   The patient felt if a person had been intoxicated or on medication or had a heart condition, he did not think they would survive this. The patient was physically challenged to get through it with shallow breathing, really panting, and not being able to get around. The patient had to focus on his breathing, panting to get through it. It was serious for him. Initially he noticed the change in his pulse rate and kept checking his pulse. His normal is usually 60 but in this case, it was 56 to 60. The anxiety was mild, he was concentrating to keep calm.       The patient stated: "This is a world crisis, a year old and it is not ideal conditions but this might be a critical issue in terms of the negative effects being more severe than anticipated for certain groups of people and he wanted to discuss this concern with someone at Pfizer."  The patient added he wanted to make sure that Pfizer knew that the intensity of the experience was a 100, it was very extreme. The patient added he felt like in his eye sockets and in his neck and everywhere that there was something in him, some unfamiliar sensation that has now gone away. When he bent over yesterday, he was mindful that that the dizziness had gone away. The patient added he still felt tired. The patient mentioned he did not eat for a while with that dizziness. The patient was scheduled for the next dose on 19Feb2021 but was a little unsure about getting it.     Follow-up (05Feb2021): New information reported from a contactable consumer includes: suspect vaccine (lot number; anatomical location, vaccination facility, Time), concomitant medications, reaction data (added events: Headache, Anxiety, Shallow breathing, Pulse abnormal, Exhaustion, Abnormal breathing, Feeling abnormal, Activities of daily living impaired, Body height decreased), outcomes updated and clinical course.