Received Dec 31, 2025
| Type | Name | Manufacturer | Dose | Lot | Route / Site |
|---|---|---|---|---|---|
| COVID19 | COVID19 (COVID19 (PFIZER-BIONTECH)) | PFIZER\BIONTECH | 2 | — | — |
Subacute Thyroiditis Due to COVID-19 Vaccine; This is a literature report for the following literature source(s): Case presentation: A 90-year-old female presented to community hospital with generalized weakness and altered mental status for a one-day duration prior to admission. She received a second dose of mRNA Pfizer-BioNTech COVID-19 vaccine19 days prior to her presentation to the hospital in 2021.Her first dose was administered 5 months prior, in early 2021. Review of systems was positive for nocturnal Tachycardia and 20-pound weight loss. She denied excessive sweating, heat intolerance, or neck pain. Her past medical history was significant for Parkinson's disease, atrial flutter, hypertension, depression and mild hyponatremia. The patient had no history of thyroid disorders, contrast studies prior to admission and no prior use of amiodarone. Vitals were notable for heart rate of 101 beats per minute, blood pressure of 152/102 mmHg. She appeared anxious and disoriented. No thyromegaly, neck tenderness or neck pain was noted. Cardiac exam notable for irregular rate and rhythm. Laboratory data revealed normocytic anemia with hemoglobin 8.8g/dL (normal range,12-15 g/dL) and hyponatremia with sodium 132 mmol/L (normal range 135-145 mmol/L). Thyroid function tests revealed suppressed thyroid-stimulating hormone (TSH) 0.03 mcIU/mL (normal range: 0.50-4.50 mcIU/mL). Free thyroxine (Free T4) was 3.8 ng/dL (normal range: 0.9-1.7 ng/dL). Triiodothyronine (T3) level was not measured at the time of admission. Thyroid peroxidase antibody, thyroglobulin antibody, and thyroid-stimulating immunoglobulin were all within normal limits. C-reactive protein was elevated at 68.9 mg/L (normal range: less than 5 mg/L), and erythrocyte sedimentation rate was also elevated at 127 mm/h (normal range: less than 30 mm/h). SARS-CoV-2 test was negative. Ultrasound of the thyroid gland showed a very heterogeneous gland throughout; no large thyroid nodules were noted. No hypervascularity was observed on color flow study. Nuclear medicine I-123 thyroid uptake scan showed low thyroid uptake: the 2-hour uptake was 1.02% (normal: 5-15%) and the 24-hour uptake was not above 0 (normal: 15-35%). Thyroid biopsy was not indicated. Biochemical, Hormonal, and imaging studies confirmed the diagnosis of thyrotoxicosis, likely due to subacute thyroiditis associated with the mRNA Pfizer-BioNTech COVID-19 vaccine administration. The patient was resumed on her home dose of metoprolol 25 mg twice daily, and prednisone 30 mg daily was started. The patient's tachycardia improved, and she was discharged. When the patient returned for a follow-up visit two weeks later, she had clinically improved back to baseline. Hyperthyroidism improved as well: free thyroxine improved to 1.1 ng/dL (normal: 0.9-1.7 ng/dL), and TSH improved to 2.98 mcIU/mL (normal range: 0.50-4.50 mcIU/mL). Prednisone was tapered and stopped.; Sender's Comments: Based on the patient's medical history, the temporal relationship between the suspect drug and the presentation of the AE, combined with the reporter s assessment of the case, there is a reasonable possibility of causal association between the suspect drug and the adverse event of thyroiditis. 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.
Medical History/Concurrent Conditions: Atrial flutter; Depression; Hypertension; Hyponatremia; Parkinson's disease
Test Name: Anion gap; Result Unstructured Data: Test Result:14 mmol/L; Comments: at admission; Test Name: Anion gap; Result Unstructured Data: Test Result:10 mmol/L; Comments: on follow-up (16 days later); Test Name: thyroglobulin antibody; Result Unstructured Data: Test Result:less than 0.9 IU/ml; Comments: all within normal limits; Test Name: Thyroid peroxidase antibody; Result Unstructured Data: Test Result:19.1 IU/ml; Comments: all within normal limits; Test Name: Calcium; Test Result: 10.1 mg/dl; Comments: at admission; Test Name: Calcium; Test Result: 9.3 mg/dl; Comments: on follow-up (16 days later); Test Name: Chloride; Result Unstructured Data: Test Result:95 mmol/L; Comments: at admission; Test Name: Chloride; Result Unstructured Data: Test Result:98 mmol/L; Comments: on follow-up (16 days later); Test Name: Creatinine; Test Result: 0.5 mg/dl; Comments: at admission; Test Name: Creatinine; Test Result: 0.4 mg/dl; Comments: on follow-up (16 days later); Test Name: Glucose; Test Result: 120 mg/dl; Comments: at admission; Test Name: Glucose; Test Result: 137 mg/dl; Comments: on follow-up (16 days later); Test Name: Potassium; Result Unstructured Data: Test Result:4.3 mmol/L; Comments: at admission; Test Name: Potassium; Result Unstructured Data: Test Result:4.0 mmol/L; Comments: on follow-up (16 days later); Test Name: blood pressure; Result Unstructured Data: Test Result:152/102 mmHg; Test Name: Sodium; Result Unstructured Data: Test Result:132 mmol/L; Comments: at admission; Test Name: Sodium; Result Unstructured Data: Test Result:132 mmol/L; Comments: on follow-up (16 days later); Test Name: TSH; Result Unstructured Data: Test Result:0.03 uiU/mL; Comments: suppressed; Test Name: TSH; Result Unstructured Data: Test Result:17.20 uiU/mL; Comments: on outpatient follow up (24 days later); Test Name: TSH; Result Unstructured Data: Test Result:2.98 uiU/mL; Comments: improved. outpatient follow up (5 months later); Test Name: Urea nitrogen; Test Result: 18 mg/dl; Comments: at admission; Test Name: Urea nitrogen; Test Result: 30 mg/dl; Comments: on follow-up (16 days later); Test Name: Blood Urea Nitrogen/Creatinine Ratio; Result Unstructured Data: Test Result:36; Comments: at admission; Test Name: Blood Urea Nitrogen/Creatinine Ratio; Result Unstructured Data: Test Result:75; Comments: on follow-up (16 days later); Test Name: Carbon dioxide; Result Unstructured Data: Test Result:25 mmol/dL; Comments: at admission; Test Name: Carbon dioxide; Result Unstructured Data: Test Result:24 mmol/dL; Comments: on follow-up (16 days later); Test Name: Cardiac exam; Result Unstructured Data: Test Result:notable for irregular rate and rhythm; Test Name: C-reactive protein; Result Unstructured Data: Test Result:68.9 mg/l; Comments: elevated; Test Name: Estimated Glomerular Filtration Rate; Result Unstructured Data: Test Result:86; Comments: at admission unit: mL/min/1.73sqm; Test Name: Estimated Glomerular Filtration Rate; Result Unstructured Data: Test Result:107; Comments: on follow-up (16 days later) unit: mL/min/1.73sqm; Test Name: Hematocrit; Test Result: 28.5 %; Comments: at admission; Test Name: Hematocrit; Test Result: 36.7 %; Comments: on follow-up (16 days later); Test Name: Hemoglobin; Result Unstructured Data: Test Result:8.8 g/dl; Comments: at admission; Test Name: Hemoglobin; Result Unstructured Data: Test Result:11.3 g/dl; Comments: on follow-up (16 days later); Test Name: heart rate; Result Unstructured Data: Test Result:101; Comments: beats per minute; Test Name: imaging studies; Result Unstructured Data: Test Result:confirmed the diagnosis of thyrotoxicosis; Comments: likely due to subacute thyroiditis associated with the mRNA Pfizer-Bio-NTech COVID-19 vaccine administration; Test Name: Biochemical; Result Unstructured Data: Test Result:confirmed the diagnosis of thyrotoxicosis; Comments: likely due to subacute thyroiditis associated with the mRNA Pfizer-Bio-NTech COVID-19 vaccine administration; Test Name: hormonal; Result Unstructured Data: Test Result:confirmed the diagnosis of thyrotoxicosis; Comments: likely due to subacute thyroiditis associated with the mRNA Pfizer-Bio-NTech COVID-19 vaccine administration; Test Name: Review of systems; Test Result: Positive ; Comments: for nocturnal tachycardia; Test Name: 24-h uptake; Result Unstructured Data: Test Result:was not above 0 %; Test Name: 2-h uptake; Test Result: 1.02 %; Test Name: Thyroid uptake scan; Result Unstructured Data: Test Result:low thyroid uptake; Comments: Nuclear medicine I-123; Test Name: Mean Corpuscular Hemoglobin; Test Result: 29.0 pg; Comments: at admission; Test Name: Mean Corpuscular Hemoglobin; Test Result: 28.9 pg; Comments: on follow-up (16 days later); Test Name: Mean corpuscular volume; Result Unstructured Data: Test Result:94.1; Comments: at admission Unit: fL; Test Name: Mean corpuscular volume; Result Unstructured Data: Test Result:93.9; Comments: on follow-up (16 days later) Unit: fL; Test Name: Platelet count; Result Unstructured Data: Test Result:367 x10 3/mm3; Comments: at admission; Test Name: Platelet count; Result Unstructured Data: Test Result:394 x10 3/mm3; Comments: on follow-up (16 days later); Test Name: erythrocyte sedimentation rate; Result Unstructured Data: Test Result:127; Comments: elevated unit: mm/h; Test Name: SARS-CoV-2 test; Test Result: Negative ; Test Name: thyroid; Result Unstructured Data: Test Result:Hyperthyroidism improved as well; Test Name: thyroid stimulating immunoglobulin; Result Unstructured Data: Test Result:less than 89 %; Comments: all within normal limits; Test Name: free thyroxine (freeT4); Result Unstructured Data: Test Result:3.8 ng/dL; Test Name: free thyroxine (freeT4); Result Unstructured Data: Test Result:1.0 ng/dL; Comments: improved; Test Name: free thyroxine (freeT4); Result Unstructured Data: Test Result:1.1 ng/dL; Comments: improved; Test Name: Color flow image on thyroid ultrasound; Result Unstructured Data: Test Result:No hypervascularity noted; Test Name: Ultrasound of the thyroid gland; Result Unstructured Data: Test Result:a very heterogenous gland throughout,; Comments: no large thyroid nodules were noted; Test Name: Vitals; Result Unstructured Data: Test Result:notable for heart rate of 101beats per; Comments: minute, blood pressure of 152/102mmHg. She appeared anxious and disoriented. No thyromegaly, neck tenderness or neck pain was noted.; Test Name: weight; Result Unstructured Data: Test Result:20-pound weight loss lbs; Test Name: White Blood Cell count; Result Unstructured Data: Test Result:5.53 x10 3/mm3; Comments: at admission; Test Name: White Blood Cell count; Result Unstructured Data: Test Result:7.44 x10 3/mm3; Comments: on follow-up (16 days later)