Congestive cough; Weakness; didn't have an appetite; legs felt stiff, or almost frozen; Severe muscle weakness/extreme weakness was only in her mother's lower body; tremendous fatigue/Tiredness; Couldn't walk; This is a spontaneous report from contactable consumers. An 86-year-old female patient (mother) received the first dose of BNT162B2 (PFIZER-BIONTECH COVID-19 VACCINE) via an unspecified route of administration at left arm on 12Jan2021 10:15 at single dose for COVID-19 immunization. Medical history included ongoing chronic obstructive pulmonary disease (COPD) for years; COVID-19 Virus from 23Apr2020 to an unknown date, patient was not on a vent or in the ICU but did receive plasma as part of her COVID-19 Virus treatment; ongoing cough. Caller's grandmother had Multiple Sclerosis. There were no concomitant medications. The patient received her first Pfizer COVID-19 Vaccine dose, and had significant side effects. Patient weight was 175 lbs as provided by caller, who stated her mother recently moved into an independent living facility, and gained weight because the facility has a really good pastry chef. Patient height, reported her mother shrunk, and was 5'5-1/2". Reported her mother couldn't walk after receiving the first dose. She said her mother was not able to walk the next morning, 13Jan2021. The caller stated she had to spend 3 days with her mother, after her mother received her first COVID-19 Vaccine dose on 12Jan2021. Reported she thought initially what her mother was experiencing was either neurological or muscular. She said it was like her mother's brain wanted her to move, but her mother's legs wouldn't move. She said her mother needed to use a walker and have someone hold her from behind. She said now, at a week later, her mother still was not back to normal. She clarified her mother needed a walker to maneuver around, but didn't need someone holding her from behind. Reported she assumed her mother may have had tiredness, weakness, severe muscle weakness from receiving the first COVID-19 Vaccine dose. She clarified if her mother wasn't able to walk after receiving the first COVID-19 Vaccine dose, then what her mother had was the epitome of weakness, and the weakness was only in her mother's lower body. She said her mother had tremendous fatigue on days 2, 3, and 4 after receiving the first dose. She said her mother was able to function as of 19Jan2021, but her mother couldn't keep her eyes open during that time period. Reported her mother developed a congestive cough. She said her mother's cough was not continual, but persisting. She stated her mother said the cough was there before she had her first dose of the COVID-19 Vaccine. The caller stated she disagreed with her mother. She said her mother has COPD, but her mother was not a cougher. She said her mother's cough now, reminded her of the cough her mother had when her mother had the COVID-19 Virus in 2020. She clarified her mother was tested on 23Apr2020 for the COVID-19 Virus, and diagnosed positive for the virus on 24Apr2020. The caller said she was perplexed by her mother's cough, and her mother will be seeing her doctor this Thursday, 21Jan2021. She said she gave her mother some Robitussin for the cough. She said her mother's cough was not persistent, but the cough was still there. She said her mother's cough was not constant, but her mother's cough was congested. She said she didn't know when her mother's cough started. She said she thought giving her mother the Robitussin doses was kind of insignificant, because her mother did not have a constant cough, where she needed to take the Robitussin. She said her mother didn't even use half of a normal sized Robitussin bottle. Caller stated she did not have the Robitussin UPC, Lot, and Expiration Date. Reported her mother has an annual lung x-ray and MRI, clarifying she believed her mother had both within the past 3 months. Reported her mother was concerned about receiving the second COVID-19 Vaccine dose. She said she told her mother that it was better to get the second dose of the COVID-19 Vaccine than to get the COVID-19 Virus again. Reported her mother had asked her primary care doctor if she should get the COVID-19 Vaccine, and her doctor told her absolutely. She said her doctor told her she needed to take the COVID-19 Vaccine even if she had the plasma treatment with the COVID-19 Virus in Apr2020. Reported she planned to stay with her mother after her mother received the second COVID-19 Vaccine dose. She said she didn't anticipate her mother having a reaction after the first COVID-19 Vaccine dose because people said most reactions are happening after getting the second COVID-19 Vaccine dose. She said now people are reporting having reactions after the first COVID-19 Vaccine dose. Reported she thought her mother's side effect after having the COVID-19 Vaccine to be unusual, since most people say it feels like they have the flu, or they are tired, or they have a headache. Reported her mother not to be able to walk wasn't that her mother was not walking, but that her mother's foot wouldn't move. She said mother not walking was either neurologic or muscular, unless that is what extreme weakness is. She said she wondered if others have experienced what her mother has. She said if her mother was experiencing just extreme weakness, the extreme weakness was only in her mother's lower body, not in her upper body. She said her mother didn't have an appetite, but her mother was not too weak to put a spoon to her mouth. She said her mother couldn't move her legs, and her mother said her legs felt stiff, or almost frozen. She said if her mother had extreme weakness, and couldn't walk, what did that mean. She said if a person is really tired, the person can still move and get out of bed. She said her mother said she was really, really tired, and couldn't move. The caller said her mother said she couldn't move, and it took her mother 20 minutes to get her legs over the side of the bed. She said her mother not being able to move her legs could be extreme weakness, but observing her mother first hand, she said it looked like her mother not being able to move her legs was neurologic. She said her mother was strong in character and body, and her mother would do everything she could in her body to move, but it was like her mother's brain said "go", and her body said "not now". The outcome of the event Congestive cough was not recovered, of the other events was unknown.   Information on the lot/batch number has been requested.