Patient characteristics
| Characteristic . | Patient 1 . | Patient 2 . | Patient 3 . | Patient 4 . | 
|---|---|---|---|---|
| Age, y | 72 | 71 | 66 | 64 | 
| Sex | Male | Female | Male | Female | 
| Preexisting conditions and past medical history | Radioiodine-treated autoimmune thyroiditis | Latent hyperthyroidism, nodular goiter, breast cancer, stroke | Hypertension, mild thrombocytopenia | Hypertension, chronic obstructive pulmonary disease, steatosis hepatis | 
| Allergies | Pollen | None | None | None | 
| Medication on admission | None | Aspirin, metamizole, denosumab (once every 6 mo) | Amlodipine, valsartan, hydrochlorothiazide, tamsulosin | Candesartan, hydrochlorothiazide, zolpidem, salbutamol, tilidine, tiotropium bromide | 
| Time from vaccination to admission, days | 11 | 11 | 2 | 15 | 
| Symptoms | Petechiae, epistaxis, headache | Petechiae, hyposphagma | Petechiae | None | 
| Platelet count nadir × 109/L | <5 | <5 | <5 | 6 | 
| D-dimer peak, mg/L (reference range, 0.21-0.52 mg/L FEU) | 0.83 | 1.16 | 0.35 | 0.51 | 
| PF4-polyanion antibodies (ELISA) | Negative | Negative | Negative | Negative | 
| Treatment | Intravenous immunoglobulin, glucocorticoids | Intravenous immunoglobulin, glucocorticoids, thrombopoietin receptor agonist | Glucocorticoids | Glucocorticoids | 
| Characteristic . | Patient 1 . | Patient 2 . | Patient 3 . | Patient 4 . | 
|---|---|---|---|---|
| Age, y | 72 | 71 | 66 | 64 | 
| Sex | Male | Female | Male | Female | 
| Preexisting conditions and past medical history | Radioiodine-treated autoimmune thyroiditis | Latent hyperthyroidism, nodular goiter, breast cancer, stroke | Hypertension, mild thrombocytopenia | Hypertension, chronic obstructive pulmonary disease, steatosis hepatis | 
| Allergies | Pollen | None | None | None | 
| Medication on admission | None | Aspirin, metamizole, denosumab (once every 6 mo) | Amlodipine, valsartan, hydrochlorothiazide, tamsulosin | Candesartan, hydrochlorothiazide, zolpidem, salbutamol, tilidine, tiotropium bromide | 
| Time from vaccination to admission, days | 11 | 11 | 2 | 15 | 
| Symptoms | Petechiae, epistaxis, headache | Petechiae, hyposphagma | Petechiae | None | 
| Platelet count nadir × 109/L | <5 | <5 | <5 | 6 | 
| D-dimer peak, mg/L (reference range, 0.21-0.52 mg/L FEU) | 0.83 | 1.16 | 0.35 | 0.51 | 
| PF4-polyanion antibodies (ELISA) | Negative | Negative | Negative | Negative | 
| Treatment | Intravenous immunoglobulin, glucocorticoids | Intravenous immunoglobulin, glucocorticoids, thrombopoietin receptor agonist | Glucocorticoids | Glucocorticoids | 
ELISA, enzyme-linked immunosorbent assay; FEU, fibrinogen equivalent units.