she slept and had no energy; Booster Dose: Legs didn''t work and had to have help to bathroom; she was like a mop and couldn't walk; Booster Dose: Legs didn''t work and had to have help to bathroom; she was like a mop and couldn't walk; Booster Dose: Tiredness, sleeping most of the time; Booster Dose: Tiredness, sleeping most of the time; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP) from medical information team. Other Case identifier(s): US-PFIZER INC-202200019589 (Pfizer).  A 76 year-old female patient received bnt162b2 (BNT162B2), administered in arm right, administration date 23Dec2021 (Lot number: FF8841) at the age of 76 years as dose 3 (booster), single for covid-19 immunisation. The patient's relevant medical history was not reported. There were no concomitant medications. Vaccination history included: Bnt162b2 (Second Dose: 24Feb2021 , Lot: Unknown), administration date: 24Feb2021, when the patient was 75 years old, for COVID-19 immunization, reaction(s): "Soreness"; Bnt162b2 (First Dose: 05Feb2021 , Lot: Unknown), administration date: 05Feb2021, when the patient was 75 years old, for COVID-19 immunization, reaction(s): "Soreness".  The following information was reported: MOBILITY DECREASED (non-serious), GAIT DISTURBANCE (non-serious) all with onset 24Dec2021, outcome "recovered" (27Dec2021) and all described as "Booster Dose: Legs didn''t work and had to have help to bathroom; she was like a mop and couldn't walk"; HYPERSOMNIA (non-serious), FATIGUE (non-serious) all with onset 24Dec2021, outcome "recovered" and all described as "Booster Dose: Tiredness, sleeping most of the time"; ASTHENIA (non-serious), outcome "unknown", described as "she slept and had no energy". The events "booster dose: legs didn''t work and had to have help to bathroom; she was like a mop and couldn't walk", "booster dose: legs didn''t work and had to have help to bathroom; she was like a mop and couldn't walk", "booster dose: tiredness, sleeping most of the time" and "booster dose: tiredness, sleeping most of the time" were evaluated at the physician office visit. Therapeutic measures were not taken as a result of mobility decreased, gait disturbance, hypersomnia, fatigue.  Additional information: Prior Vaccinations (within 4 weeks) None. AE(s) following prior vaccinations: None. Patient's Medical History (including any illness at time of vaccination)? None. Family Medical History Relevant to AE(s): None. Relevant Tests: None. Caller states on 23Dec2021 his wife and him were in (state) for Christmas and they live in (state) , but his wife chose to have her booster shot on 23Dec2021. Caller states on the morning of 24Dec2021, she had an adverse reaction, her legs didn't work and she had to have help to the bathroom and she was sleeping most of the time and was tired. She was like a mop and couldn't walk. Caller states they actually thought about taking her to the hospital but it is full of Covid patients. Caller states they tried calling the health department who gave her the shot there, but there was no response, they tried time and time again. Caller states it seems like she had a severe reaction, has Pfizer heard of a reaction like this?. Treatment: None. Caller states the patient went to see her own doctor once she got back to and the doctor said it seems like she had a severe adverse reaction. Caller states the Doctor was asking maybe it was a live virus vs dead virus?. Caller states when they got back to (state), his wife went to see her primary physician who thought she had a serious AE and he suspected that she did not get the live vaccine. Caller would like to know if we can tell him if his wife received the live or dead vaccine based on the lot number?