½ cup of blood was removed from knee joint in ER; diagnosis that she had fluid in her knee; On Sunday 27Mar2021, three of her joints swelled and caused her pain.  All three joints were the subject a joint replacement at some point in the past.  Her knee cause her the most pain, worsening t; On Sunday 27Mar2021, three of her joints swelled and caused her pain.  All three joints were the subject a joint replacement at some point in the past.  Her knee cause her the most pain, worsening t; This is a spontaneous report received from contactable reporter(s) (Consumer or other non HCP).  A 74 year-old female patient (not pregnant) received bnt162b2 (BNT162B2), administered in arm left, administration date 25Mar2021 (Lot number: ER8730) at the age of 74 years as dose 2, single for covid-19 immunisation. Relevant medical history included: "arthritis" (unspecified if ongoing); "afib" (unspecified if ongoing). Concomitant medication(s) included: ELIQUIS; DILTIAZEM HCL; IRON [FERROUS SULFATE]; FLECAINIDE; FUROSEMIDE; CULTURELLE; LATANOPROST; METOPROLOL; OMEPRAZOLE; ARMOUR THYROID; VITAMIN D3. Vaccination history included: Bnt162b2 (1st dose, {product=COVID 19, brand=Pfizer,, lot_number=EN6202,, lot_unknown=False,, administration_date=25Feb2021,, vaccine_location=Left arm,, dose_number=1}]), administration date: 25Feb2021, when the patient was 74 years old, for COVID-19 immunisation, reaction(s): "No reaction on previous exposure to vaccine". The following information was reported: HAEMARTHROSIS (medically significant) with onset 27Mar2021, outcome "recovering", described as "½ cup of blood was removed from knee joint in ER"; JOINT EFFUSION (non-serious) with onset 27Mar2021, outcome "recovering", described as "diagnosis that she had fluid in her knee"; JOINT SWELLING (non-serious), PAIN (non-serious) all with onset 27Mar2021, outcome "recovering" and all described as "On Sunday 27Mar2021, three of her joints swelled and caused her pain.  All three joints were the subject a joint replacement at some point in the past.  Her knee cause her the most pain, worsening t". The event "½ cup of blood was removed from knee joint in er" was evaluated at the physician office visit. The events "diagnosis that she had fluid in her knee", "on sunday 27mar2021, three of her joints swelled and caused her pain.  all three joints were the subject a joint replacement at some point in the past.  her knee cause her the most pain, worsening t" and "on sunday 27mar2021, three of her joints swelled and caused her pain.  all three joints were the subject a joint replacement at some point in the past.  her knee cause her the most pain, worsening t" were evaluated at the emergency room visit. The patient underwent the following laboratory tests and procedures: blood test: without sign of infection., notes: The next day she visited her orthopedic physician whereupon they removed 3/4 cup of blood from her joint. The next day she returned, and they removed 1/2 cup of blood from the joint. Blood was tested without sign of infection. She was taken off the Eliquis. Her knee is now improving. Therapeutic measures were taken as a result of joint effusion, joint swelling, pain.  Additional information: On Sunday 27Mar2021, three of her joints swelled and caused her pain. All three joints were the subject a joint replacement at some point in the past. Her knee causes her the most pain, worsening throughout the day until she could no longer use her limb due to the pain. She went to the emergency room that evening with the diagnosis that she had fluid in her knee. Prior to the vaccination, the patient was not diagnosed with COVID-19. Since the vaccination, the patient had not been tested for COVID-19. The patient did not receive any other vaccines within four weeks prior to the vaccination.  No follow-up attempts are possible. No further information is expected.; Sender's Comments: Linked Report(s) : US-PFIZER INC-2021358925 similar report from same reporter