Suspected vaccination failure; Mealses; Rubella; Fever; Malaise; Rash; hepatomegaly; This case was reported in a literature article and described the occurrence of vaccination failure in a 2-year-old female patient who received MMR (MMR vaccine) for prophylaxis.   The patient's past medical history included neonatal sepsis (hospitalized for 10 days, for neonatal sepsis, in the first month of life), fever (hospitalized at 2 ,3 months of age), dyspnea (hospitalized at 2 ,3 months of age), diarrhea (hospitalized at 3, 5 months), vomiting (hospitalized at 5 months of age), hand, foot and mouth disease (hospitalized at 8 months of age), kawasaki's disease (diagnosed at the age of 11 months), rash (at the age of 11 months), aphthous stomatitis (hospitalized at 13 months of age), covid-19 pneumonia (hospitalized for 10 days at age of 1.5 years), death (Family History) (a second child in this family died at the age of 5 months without a definitive diagnosis) and hospitalization (At 1,2,3,5,8,13 months ,1.5 yrs of age). Previously administered products included BCG vaccine with an associated reaction of no adverse event (at birth), azithromycin, hydroxychloroquine and IVIG (Kawasaki fever). Concurrent medical conditions included protein deficiency (TYK2 deficiency). Additional patient notes included patient did not require oxygen therapy for acute COVID-19 pneumonia. The patient had no mycobacterial and other infection..   On an unknown date, the patient received MMR vaccine. On an unknown date, unknown after receiving MMR vaccine, the patient experienced vaccination failure (serious criteria hospitalization and GSK medically significant), measles (serious criteria hospitalization and GSK medically significant), rubella (serious criteria hospitalization), fever (serious criteria hospitalization), malaise (serious criteria hospitalization), rash (serious criteria hospitalization) and hepatomegaly (serious criteria hospitalization). On an unknown date, the outcome of the vaccination failure, measles, rubella, fever, malaise, rash and hepatomegaly were unknown.   It was unknown if the reporter considered the vaccination failure, measles, rubella, fever, malaise, rash and hepatomegaly to be related to MMR vaccine.     Additional Information: GSK Receipt Date: 12-Dec-2022  Author's comment: This patient was a girl born to second degree consanguineous parents. The patient was vaccinated with Bacille Calmette-Geurin at birth without complications. The patient was hospitalized for 10 days, for neonatal sepsis, in the first month of life. The patient was then hospitalized twice in the ICU: at 2 months of age for fever and dyspnea (3 days in the Intensive care unit (ICU)), and then at 3 months of age for fever, diarrhea, and dyspnea (14 days in the ICU). The patient was hospitalized at 5 months of age for diarrhea and vomiting, and at 8 months of age for hand-foot-and mouth disease. At the age of 11 months, the patient was diagnosed with Kawasaki disease (fever and rash). At the age of 13 months, the patient was hospitalized for aphthous stomatitis. At the age of 1.5 years, the patient was hospitalized for 10 days for acute COVID-19 pneumonia (polymerase chain reaction-positive); The patient did not require oxygen therapy. The patient was treated with azithromycin and hydroxychloroquine. At the age of 2 years, following Measles, Mumps and Rubella (MMR) vaccination (delayed due to the intravenous immunoglobulin (IVIG) used to treat Kawasaki fever), the patient developed fever, malaise, rash, and hepatomegaly (requiring hospitalization). The patient was diagnosed with rubella/measles (confirmed by the detection of Immunoglobulin G (IgG) against measles). A second child in this family died at the age of 5 months without a definitive diagnosis, after suffering from dyspnea, icterus, and hypotonia since the age of 2 months. No genetic analysis was possible for this child. Additional supportive information: The article corresponding to this case is not available for regulatory submission due to copyright restriction. This case was considered as suspected vaccination failure as details regarding completion of primary vaccination schedule, time to onset for target disease were unknown at the time of reporting.; Reporter's Comments: e20220094