Large swollen lump in left arm pit; Large swollen lump in left arm pit with soreness; This is a spontaneous report received from a contactable reporter(s) (Consumer or other non HCP). The reporter is the patient. A 71 year-old female patient (not pregnant) received bnt162b2 (BNT162B2), intramuscular, administered in arm left, administration date 25Oct2021 23:00 (Lot number: 38135BA) at the age of 71 years as dose 3 (booster), single for covid-19 immunisation. Relevant medical history included: "Penicillin allergy" (unspecified if ongoing), notes: I am allergic to penicillin (rash); "Acid reflux" (unspecified if ongoing); "BP" (unspecified if ongoing); "Plaque" (unspecified if ongoing); "Probiotic" (unspecified if ongoing); "IBS" (unspecified if ongoing); "Dental Surgery Antibiotic" (unspecified if ongoing); "Allergies/Nasal Drip" (unspecified if ongoing); "Allergies/Nasal Drip" (unspecified if ongoing); "IBS cramping" (unspecified if ongoing). Concomitant medication(s) included: OMEPRAZOLE taken for gastrooesophageal reflux disease; AMLODIPINE taken for blood pressure measurement, start date: 20Jan2021; VALSARTAN taken for blood pressure measurement, start date: 29Mar2021; ROSUVASTATIN taken for dental plaque; BABY ASPIRIN; VITAMIN D NOS; CULTURELLE taken for probiotic therapy; COQ10 [ASCORBIC ACID;BETACAROTENE;CUPRIC OXIDE;MANGANESE SULFATE;SELENIUM;TOCOPHERYL ACETATE;UBIDECARENONE;ZINC OXIDE]; CLARITIN-D; DICYCLOMINE taken for irritable bowel syndrome; GAS X taken for irritable bowel syndrome; NASACORT ALLERGY 24 HR taken for hypersensitivity, upper-airway cough syndrome; XANAX; MAGNESIUM taken for muscle spasms; CLINDAMYCIN taken for dental operation; AZITHROMYCIN. Vaccination history included: Bnt162b2 (Dose Number: 1, Batch/Lot number: EL9269, Location of injection: Arm Left, Vaccine Administration Time: 12:00 PM, Route of administration: Intramuscular), administration date: 14Feb2021, when the patient was 70 years old, for COVID-19 Immunization; Bnt162b2 (Dose Number: 2, Batch/Lot number: EN6205, Location of injection: Arm Left, Vaccine Administration Time: 12:00 PM, Route of administration: Intramuscular), administration date: 08Mar2021, when the patient was 70 years old, for COVID-19 Immunization, reaction(s): "chills", "headache", "fatigue", "pink rash on body"; Flu shot (Anatomical location: Left arm), administration date: 04Oct2021, when the patient was 71 years old, for immunization. The following information was reported: SWELLING (non-serious) with onset 26Oct2021 15:00, outcome "recovered", described as "Large swollen lump in left arm pit"; AXILLARY PAIN (non-serious) with onset 26Oct2021 15:00, outcome "recovered", described as "Large swollen lump in left arm pit with soreness". Relevant laboratory tests and procedures are available in the appropriate section. Therapeutic measures were not taken as a result of swelling, axillary pain.  Additional information: No Covid prior vaccination. Tested for covid post vaccination (nasal swab). Large swollen lump in left arm pit subsided in 10 days (seems back to normal now) and Soreness was present for 2 days only. The patient was receiving One a day womens 1 per day as concomitant medication. No Relevant Tests. No specific relevant test for thromboembolic events with thrombocytopenia.  No follow-up attempts are possible. No further information is expected.