she was just not feeling it/ It's like she had a brain fog; It was good before and now after shot does not feel good; she had a low-grade fever of 100; Trouble concentrating; Felt hot; Runny nose; Weak; Tired; No stamina; This is a spontaneous report received from contactable reporter(s) (Other HCP) from medical information team. The reporter is the patient. Other Case identifier(s): US-PFIZER INC-202101391998 (Pfizer).  A 50-year-old female patient received bnt162b2 (BNT162B2), administered in deltoid left, administration date 14Oct2021 17:00 (Lot number: FF8839) at the age of 50 years as dose 3 (booster), single for covid-19 immunisation. Relevant medical history included: "Blood pressure high" (unspecified if ongoing); "weight loss" (unspecified if ongoing), notes: she has been losing weight. Concomitant medication(s) included: COREG taken for hypertension (ongoing). Vaccination history included: Bnt162b2 (dose: 1, Vaccine Name: Pfizer Covid-19 Vaccine , Lot Number / Expiry Date:EH9899/UNKNOWN, Anatomical Location: Right Deltoid , Date: 15Jan2021), administration date: 15Jan2021, when the patient was 49 years old, for COVID-19 Immunization; Bnt162b2 (dose:2, Vaccine Name: Pfizer Covid-19 Vaccine , Lot Number / Expiry Date:EL3248/ UNKNOWN , Anatomical Location: , given in left deltoid , Date: 05Feb2021), administration date: 05Feb2021, when the patient was 49 years old, for COVID-19 immunization; Shingles shot (had Shingles sot six weeks ago). The following information was reported: ASTHENIA (non-serious) with onset 14Oct2021, outcome "not recovered", described as "Weak"; FATIGUE (non-serious) with onset 14Oct2021, outcome "not recovered", described as "Tired"; FATIGUE (non-serious) with onset 14Oct2021, outcome "not recovered", described as "No stamina"; DISTURBANCE IN ATTENTION (non-serious) with onset 15Oct2021, outcome "not recovered", described as "Trouble concentrating"; FEELING HOT (non-serious) with onset 14Oct2021, outcome "recovered" (15Oct2021), described as "Felt hot"; RHINORRHOEA (non-serious) with onset 14Oct2021, outcome "recovered" (15Oct2021), described as "Runny nose"; PYREXIA (non-serious) with onset 15Oct2021, outcome "unknown", described as "she had a low-grade fever of 100"; FEELING ABNORMAL (non-serious), outcome "unknown", described as "she was just not feeling it/ It's like she had a brain fog"; MALAISE (non-serious), outcome "unknown", described as "It was good before and now after shot does not feel good". Relevant laboratory tests and procedures are available in the appropriate section. Therapeutic measures were taken as a result of feeling hot, pyrexia.  Additional information: The patient previously got the two Pfizer Covid doses, one in Jan and other Feb. The patient had a different reaction this time around than she did with the other two. The patient got the booster shot at 5 pm on 14Oct2021. The patient had the normal scenario like when get the flu shot, feeling hot, runny nose, whatever. However, as the days went on the patient was feeling, weak, tired, having concentration problems, no stamina. The patient had to take day off work as the patient was just not feeling it. It was good before and now after shot does not feel good. The patient's Weakness assumed due to getting shot. It's like the body was going through all processes it goes through when getting a shot. It's typical. The patient was tired like body trying to fight vaccine. The patient's trouble concentrating was like she had a brain fog. This was what she was most concerned with. When probed for seriousness criteria of weak, tired, no stamina, and trouble concentrating: It made her take a day off work, The patient was nervous. It was not life disabling, but it interrupted her life. The patient had to be on the ball as a nurse. The patient felt hot within 20 minutes of getting the shot. Her temperature was checked ant it was 97.6. The patient figures it was just antibodies kicking in. On 15Oct2021 the patient had a low-grade fever of 100 and then the hotness went away after taking Tylenol. Blood pressure has been stabilizing, she has been losing weight. Works in healthcare, in in long term with the elderly. She got it to protect them. patient did not want to catch covid and give to them. Patient Stated, she has not gone to the doctor's yet, but she may depending on what we say. Commented hear stories, but no additional details provided. Prior Vaccinations within 4 weeks patient had Shingles sot six weeks ago. She was going to get the flu shot, but instead decided to get the booster.  Follow-up attempts completed. No further information expected.