Caller had a vaccine last week, severe reaction, difficulty breathing.; felt strange right away.She was kind of out of it.; hard time walking; heart beating so strong; This is a spontaneous report from a contactable consumer via Pfizer-sponsored program. A 86-year-old female patient received bnt162b2 (PFIZER-BIONTECH COVID-19 mRNA VACCINE, Formulation: Solution for injection, Batch/Lot Number: EM9809, Expiration date: Unknown), via an unspecified route of administration, in right arm on 08Feb2021 at 14:00 (at the age of 86-year-old) as dose 1, single for COVID-19 immunisation. The patient medical history included thyroid disorder from an unknown date and unknown if ongoing, ongoing urinary tract disorder, mastectomy, and lymphadenectomy from an unknown date and unknown if ongoing 35 years ago, on the right side. Investigations were unknown. The patient had no family medical history. The patient concomitant medications were reported as unknown. The patient did not receive any other vaccines within 4 weeks prior to the COVID vaccine. No additional vaccines administered on same date of Pfizer suspect was administered. Adverse events follow prior vaccinations was reported as none. On an unspecified date, caller had a vaccine in the last week and experienced severe reaction, difficulty breathing, felt strange right away. she was kind of out of it, hard time walking, heart beating so strong. It was reported that, had COVID vaccine three weeks ago and had very severe side effects. was told to call on morning of second COVID vaccine to see if she should get it or not. She was due for her second COVID vaccine today, 01Mar2021 at 2PM. When she had the side effects, she was taken care of. Her blood pressure and heart rate were taken. She was kept there for quite some time. She left without asking if she should get the second COVID shot or not. Already had an appointment with him Friday and went over her severe side effects. (Name) could not come up with an answer as to if she should receive the second COVID shot. One of her papers says, "people who should not get a second shot is if you had severe side effects, "but she never discussed that with the vaccination clinic. She was on the phone all day yesterday and did fill out some questions. She spoke with someone who had communication issues. She does not have a reference number and could not confirm if she filed a report with Regulatory Authority. Clarified severe side effects as soon as the needle went into her arm, she felt strange right away. She was kind of out of it. She got up to go to the room and had a hard time walking. She felt her heart beating so strong in her chest that she could almost see it. She was not nervous going in, but very relaxed. Her heart was beating very quickly after the COVID shot. She did not want to tell anyone initially. After a nurse came by and asked if she was ok, she finally admitted she was not. She was then taken by the nurse at the vaccine clinic where caller was worked on. She was never told if she should receive the second vaccine or not. It lasted a while at the vaccine clinic, maybe a good 30-40 minutes and she was fine when she came home. Stated she received first dose COVID Vaccine three weeks ago on 01Mar2021 but provided date of 08Feb2021 from patient record card. Wondered if that has anything to do with it. She has not been able to get any blood taken on the right arm until 6 months ago. She had blood work done yesterday and it was drawn from her left arm. No adverse event required a visit to emergency room. Had an appointment last week for a regular physical. She came straight home after the COVID vaccine because she felt fine. At the end of her regular physical, her primary care said maybe she could get the second COVID vaccine. Her reaction kind of scared her. The patient underwent lab tests and procedures which included blood pressure measurement: unknown result on, heart rate: unknown result. No product complaint was reported. The outcome of the events was reported as unknown.  No follow-up attempts are possible. No further information is expected.