marked edema in the gray matter of the upper spinal cord (C1-T5), with expansile T2 hyperintensity most consistent with myelitis of infectious or postvaccinal etiology/ transverse myelitis; This literature marketed report as received from the authors of the published article and refers to a 4-month-old male patient. The patient's medical history included ventricular septal defect. His concurrent conditions and concomitant medications were not reported.  On an unknown date, the patient was vaccinated with haemophilus b conjugate vaccine (meningococcal protein conjugate) (LIQUID PEDVAXHIB); diphtheria toxoid, hepatitis b virus vaccine rhbsag (yeast), pertussis acellular 3-component vaccine, poliovirus vaccine inactivated (vero), tetanus toxoid (PEDIARIX); rotavirus vaccine, live, oral, pentavalent (ROTATEQ) and pneumococcal 13v conj vaccine (CRM197) (reported as pneumococcal conjugate 13-valent (PCV-13)), (strength, formulation, dose, frequency, route of administration, lot# and expiration date were not reported) all administered for prophylaxis.  On an unknown date after receiving vaccinations, the patient presented with 2 days of fever and progressive weakness. He was admitted to the hospital, where he appeared lethargic, had a weak cry, and had difficulty feeding. There were no reported recent illnesses, no known sick contacts at home, and no changes to his medications. Neurological examination demonstrated low tone and weakness, with the greatest symptoms in his lower extremities. His complete blood count, as reported prior to the first therapeutic plasma exchange (TPE), showed a white blood cell (WBC) count of 18.5 × 10^9/L, a hemoglobin level of 114 g/L, an hematocrit (HCT) of 34%, and a platelet count of 542 × 10^9/L. Magnetic resonance imaging revealed marked edema in the gray matter of the upper spinal cord (C1-T5), with expansile T2 hyperintensity most consistent with myelitis of infectious or postvaccinal etiology and he was diagnosed with transverse myelitis. The remainder of the spine appeared normal. Lumbar puncture with spinal fluid analysis showed nucleated cells at 58 × 10^6/L, red blood cells (RBCs) at 11 × 10^6/L and a WBC differential count of 50% neutrophils, 48% macrophages, and 2% lymphocytes. The glucose level was 6.216 mmol/L, and the protein level was 1060 mg/L. Initial therapy based on a diagnosis of transverse myelitis consisted of 261 mg (30 mg/kg) intravenous (IV) glucocorticosteroid (methylprednisolone) daily for 5 days and 8.7 g (1 g/kg) IV immunoglobulin (IVIg) daily for 2 days. Despite this treatment, there was no improvement in the patient's neurologic exam. Five single-plasma volume TPEs were planned and performed every other day. Normal saline (0.9% sodium chloride) was used to prime the machine and then it was displaced with the CP. Anticoagulant citrate dextrose solution A, that is, acid citrate dextrose solution A, was used as a regional anticoagulant at an anticoagulant-to-whole blood ratio of 1:10-15. All procedures were performed using a central venous dialysis catheter placed in the right internal jugular vein. Repeat TPE was performed 2 days later, with no technical complications. Prior to the start of the third procedure, it was noted that the patient's HCT had increased after each of the prior TPEs. The patient's HCT increased from 34% to 38% after the first aborted procedure and from 38% to 42% after the repeated TPE. HCT was measured and adjusted for the final TPE procedures and subsequently the patient's HCT did not increase and remained in the 40%-42% range for the remainder of his hospital stay. After completion of the final session of TPE, the patient received two extra doses of IVIg to replace any immunoglobulins that were removed secondary to the TPE. Despite completion of therapy, he continued to demonstrate muscle weakness, decreased balance and coordination, abnormal tone, and impaired mobility. He was scheduled for physical therapy visits after discharge with the hope of improving and/or restoring strength and balance, as determined by the inpatient physical therapy team. The action taken with suspect vaccines was not applicable.  The reporter considered transverse myelitis to be related to suspect vaccines or infection. Upon internal review, transverse myelitis was considered to be medically significant.  A copy of the published article is attached as further documentation of the patient's experience.