Hemolysis aggravated; fever; rigors; hemolysis aggravated; This literature-non-study case was reported in a literature article and describes the occurrence of HAEMOLYSIS (hemolysis aggravated) in a 32-year-old female patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     Concurrent medical conditions included Paroxysmal nocturnal haemoglobinuria (10-year history), Aplastic anemia and Transfusion (Transfusion dependent.). Concomitant products included RAVULIZUMAB for Paroxysmal nocturnal hemoglobinuria.   On an unknown date, the patient received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On an unknown date, received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On an unknown date, the patient experienced HAEMOLYSIS (hemolysis aggravated) (seriousness criterion medically significant), CONDITION AGGRAVATED (Hemolysis aggravated), PYREXIA (fever) and CHILLS (rigors). At the time of the report, HAEMOLYSIS (hemolysis aggravated), CONDITION AGGRAVATED (Hemolysis aggravated), PYREXIA (fever) and CHILLS (rigors) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In 2021, Aspartate aminotransferase: 25 (Inconclusive) pre-vaccination was 19units/Liter Post vaccination was 25units/liter. In 2021, Blood bilirubin: 2.7 mg/dl (Inconclusive) Pre-vaccination was 0.7 milligram/deciliter Post vaccination was 2.7 milligram/deciliter.. In 2021, Blood grouping: a positive (normal) A positive. In 2021, Blood lactate dehydrogenase: 255 (Inconclusive) Pre-vaccination was 255Units/liter. In 2021, Body temperature: 39 (High) 39 degrees celsius. In 2021, Haemoglobin: 8.4 mg/dl (Low) noted to have a 3g/dL hemoglobin decrease. Hemoglobin pre-vaccination was 11.3.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter considered HAEMOLYSIS (hemolysis aggravated), CONDITION AGGRAVATED (Hemolysis aggravated), PYREXIA (fever) and CHILLS (rigors) to be possibly related.    It was reported that the last dose of the concomitant medication ravulizumab, was given four weeks prior to vaccination. PNH Clone was reported as 39% RBC, 99% granulocytes. The patient was also reported to be part of a clinical trial with danicopan, an oral complement factor D inhibitor.  She missed two doses of danicopan immediately after her second vaccination due to concerns that the drug may interfere with vaccine potency; therefore danicopan was not at therapeutic levels at the time of her reaction.  She also took danicopan throughout her first vaccination and did not experience breakthrough hemolysis. On an unspecified date, it was reported that approximately 12 hours after receiving the second dose of the Moderna Covid-19 vaccine, the patient experienced fever and rigors. On an unspecified date, she presented to a local hospital where investigations were done.  She was transfused two units of packed red blood cells.  Based on the current available information and temporal association between the use of the product and the start date of the event, a causal relationship cannot be excluded. However, additional details regarding the subject's other medical history and concomitant medications are required for further assessment.; Sender's Comments: Based on the current available information and temporal association between the use of the product and the start date of the event, a causal relationship cannot be excluded. However, additional details regarding the subject's other medical history and concomitant medications are required for further assessment.