testing positive for COVID; testing positive for COVID; This is a spontaneous report received from a contactable reporter(s) (Pharmacist).  A 48-year-old male patient received BNT162b2 (BNT162B2), on 30Mar2021 as dose 1, single (Lot number: EM9809), on 20Apr2021 as dose 2, single (Lot number: EW0164) and on 20Dec2021 as dose 3 (booster), single (Lot number: 33130BA) at the age of 48 years, in left arm for covid-19 immunisation. The patient's relevant medical history included: "type 2 diabetes" (unspecified if ongoing); "primary HTN" (unspecified if ongoing); "kidney transplant" (unspecified if ongoing); "GERD" (unspecified if ongoing). Concomitant medication(s) included: CARVEDILOL; GABAPENTIN; INSULIN ASPART; INSULIN DEGLUDEC; MYCOPHENOLATE SODIUM; PANTOPRAZOLE; PREDNISONE; ENVARSUS XR. Past drug history included: Lisinopril, reaction(s): "Known allergies: Lisinopril", notes: Known allergies: Lisinopril. The following information was reported: VACCINATION FAILURE (hospitalization, medically significant), COVID-19 (hospitalization, medically significant) all with onset Jun2022, outcome "unknown" and all described as "testing positive for COVID". The patient was hospitalized for vaccination failure, covid-19 (hospitalization duration: 4 day(s)). The event "testing positive for covid" required physician office visit and emergency room visit. The patient underwent the following laboratory tests and procedures: tacrolimus level: (13Jun2022) 80.8 ng/ml, notes: Level was drawn on 13Jun at 04:43 and resulted at 80.8 ng/mL; (14Jun2022) 102.9 ng/ml, notes: An additional level on 14Jun am which was 102.9 ng/mL; (15Jun2022) 70.8 ng/ml, notes: Level down to 70.8 on 15Jun and patient discharged; SARS-CoV-2 test: (09Jun2022) positive, notes: Patient reported testing positive for COVID on a home test on 9Jun. Therapeutic measures were taken as a result of vaccination failure, covid-19.  Clinical course: Patient reported testing positive for COVID on a home test on 09Jun. contacted his PCP and was prescribed paxlovid (Nirmatrelvir/Ritonavir) for 5 days beginning 09Jun. The patient has taken Paxlovid  orally for the treatment of COVID-19 Treatment start date was 08Jun2022 and stop date was 11Jun2022. Patient presented to the ED (emergency department) on the afternoon of 12Jun with main c/o (complaint of) worsening severe headache as well dry cough and sore throat. Patient had taken 7 of 10 prescribed doses of Paxlovid prior to admission. Patient was on immunosuppression with Envarsus XR 4 mg daily so tacrolimus level was ordered for 13Jun due to interaction. Level was drawn on 13Jun at 04:43 and resulted at 80.8 ng/mL (therapeutic range for this patient is 4-8 ng/mL). An additional level on 14Jun am which was 102.9 ng/mL. Ordered phenytoin 300mg po daily in an attempt to increase the rate of metabolism of the tacrolimus. Level down to 70.8 on 15Jun and patient discharged. AKI (Acute kidney injury) and supra therapeutic levels resolved within days of discharge. The patient was hospitalized for 4days. Phenytoin was received as the treatment for the adverse event.; Sender's Comments: Based on plausible dose -event relationship post vaccination and no other alternate explanation the causal role of BNT162B2 cannot be excluded for the reported LOE events.