Neutropenia due to and following chemotherapy; drug ineffective; Tested positive; Malignant tumor of breast; Endometrial carcinoma; Atrial fibrillation; Essential hypertension; Gastroesophageal reflux disease; Biliary sludge; Malabsorption syndrome; This is a spontaneous report received from contactable reporter(s) (Physician).  A 73-year-old female patient received BNT162b2 (BNT162B2), on 10Oct2021 as dose number unknown (booster), 0.3 ml single (Batch/Lot number: unknown) at the age of 72 years for covid-19 immunisation. The patient's relevant medical history included: "Biopsy of bone", start date: 06Nov2018 (unspecified if ongoing), notes: R 5th rib; "Colonoscopy", start date: 07Nov2011 (unspecified if ongoing); "Lumpectomy Of right breast", start date: 01Nov2007 (unspecified if ongoing); "endometrial leiomyosarcoma", start date: 1991 (unspecified if ongoing); "TAH/BSO" (unspecified if ongoing); "non-smoker" (unspecified if ongoing). The patient's concomitant medications were not reported. The following information was reported: ATRIAL FIBRILLATION (medically significant) with onset 23Nov2021, outcome "unknown"; CHOLELITHIASIS (non-serious) with onset 23Nov2021, outcome "unknown", described as "Biliary sludge"; ENDOMETRIAL CANCER (medically significant) with onset 23Nov2021, outcome "unknown", described as "Endometrial carcinoma"; ESSENTIAL HYPERTENSION (non-serious) with onset 23Nov2021, outcome "unknown"; GASTROOESOPHAGEAL REFLUX DISEASE (non-serious) with onset 23Nov2021, outcome "unknown", described as "Gastroesophageal reflux disease"; MALABSORPTION (non-serious) with onset 23Nov2021, outcome "unknown", described as "Malabsorption syndrome"; BREAST CANCER (medically significant) with onset 23Nov2021, outcome "unknown", described as "Malignant tumor of breast"; COVID-19 (medically significant) with onset 12Jan2022, outcome "unknown", described as "Tested positive"; DRUG INEFFECTIVE (medically significant) with onset 12Jan2022, outcome "unknown"; NEUTROPENIA (medically significant) with onset 11May2022, outcome "unknown", described as "Neutropenia due to and following chemotherapy". Clinical course: Reporter stated that the patient had not been to an area to be high risk for COVID-19. In the 14 days before symptom onset, was not in close contact with a laboratory-confirmed COVID-19 while that case was ill. In tie 14 days before symptom onset, patient had no close contact with a person who is under investigation for COVID-19 while that person was ill. She did had covid vaccines and the booster on 04Nov2021. Patient Tested positive 12Jan2022.  The information on the batch/lot number for BNT162b2 has been requested and will be submitted if and when received.; Sender's Comments: Drug ineffective depends on many factors including pharmacokinetics, severity of disease and patient general health condition. However on conservative basis, the possible causality cannot be excluded.Based on the information provided in the narrative , a possible contributory role of the suspect vaccine  to reported event of breast cancer, neutropenia, endometrial cancer, atrial fibrillation, cannot be excluded. The impact of this report on the benefit/risk profile of the Pfizer product is evaluated as part of Pfizer procedures for safety evaluation, including the review and analysis of aggregate data for adverse events. Any safety concern identified as part of this review, as well as any appropriate action in response, will be promptly notified to regulatory authorities, Ethics Committees, and Investigators, as appropriate.