Swelling in left armpit and breast, the side that got the shot on / assuming this is due to the lymph nodes in this area / not painful, just swollen; Swelling in left armpit and breast, the side that got the shot on / assuming this is due to the lymph nodes in this area / not painful, just swollen; Swelling in left armpit and breast, the side that got the shot on / assuming this is due to the lymph nodes in this area / not painful, just swollen; Dose number: 3; This is a spontaneous report received from a contactable reporter(s) (Consumer or other non HCP). The reporter is the patient.  A 19 year-old female patient (not pregnant) received bnt162b2 (BNT162B2), administered in arm left, administration date 24Nov2021 (Batch/Lot number: unknown) at the age of 19 years as dose 3 (booster), single for covid-19 immunisation. Relevant medical history included: "Known allergies: Mango, kiwi" (unspecified if ongoing), notes: Known allergies: Mango, kiwi; "Known allergies: Penicillin" (unspecified if ongoing), notes: Known allergies: Penicillin. Concomitant medication(s) included: PROGESTERONE taken for contraception. Vaccination history included: Bnt162b2 (Dose 1, single ; Lot Number: unknown, Anatomical Location: Left arm; Route of Administration: Unspecified), administration date: 14Apr2021, when the patient was 18 years old, for COVID-19 immunisation; Bnt162b2 (Dose 2, single; Lot Number: unknown, Anatomical Location: Left arm; Route of Administration: Unspecified), administration date: 28Apr2021, when the patient was 18 years old, for COVID-19 immunisation, reaction(s): "Dose 1 on 14Apr2021, Dose 2 on 28Apr2021". The following information was reported: IMMUNISATION (non-serious) with onset 24Nov2021, outcome "unknown", described as "Dose number: 3"; SWELLING (non-serious), BREAST SWELLING (non-serious), LYMPHADENOPATHY (non-serious) all with onset 28Nov2021, outcome "recovering" and all described as "Swelling in left armpit and breast, the side that got the shot on / assuming this is due to the lymph nodes in this area / not painful, just swollen".  Additional Information: Prior to vaccination, the patient was not diagnosed with COVID-19. The patient did not receive any other vaccines within four weeks prior to the COVID vaccine. The event did not result in doctors or other healthcare professional office/clinic visit, and emergency room/department or urgent care. Since the vaccination, the patient had not been tested for COVID-19. Verbatim reported "I got the booster shot last Wednesday and woke up yesterday morning, (Sunday, 28Nov), to swelling in my left armpit and breast, the side I got the shot on. I'm assuming this is due to the lymph nodes in this area, but I did not have this swelling on either of my other two doses of Pfizer, so I felt I should report. Today, 29Nov, it seems to be getting better, or at least leveling out. I will see a doctor if it has not decreased by Wednesday, 01Dec. I felt it was important to note because this might freak a lot of people out, and it has the potential to freak me out if it doesn't go away in a couple days. it is not painful, just swollen". List of any other medications the patient received within 2 weeks of vaccination: Birth control 1/20 progesterone   The lot number for bnt162b2 was not provided and will be requested during follow up.