This case was reported in a literature article and described the occurrence of vaccination failure in a 3-year-old male patient who received Hepatitis A vaccine. On an unknown date, the patient received Hepatitis A vaccine (unknown). On an unknown date, unknown after receiving Hepatitis A vaccine, the patient experienced vaccination failure (serious criteria GSK medically significant), acute liver failure (serious criteria hospitalization and GSK medically significant), jaundice, urine discoloration, nausea, pruritus, hyperbilirubinemia (serious criteria GSK medically significant), hyperammonemia, hypertransaminasemia, hepatitis A and coagulopathy. The patient was treated with Blood Product Transfusion. On an unknown date, the outcome of the vaccination failure was unknown and the outcome of the acute liver failure, jaundice, urine discoloration, nausea, pruritus, hyperbilirubinemia, hyperammonemia, hypertransaminasemia, hepatitis A and coagulopathy were recovered/resolved. It was unknown if the reporter considered the acute liver failure, jaundice, urine discoloration, nausea, pruritus, hyperbilirubinemia, hyperammonemia, hypertransaminasemia, hepatitis A and coagulopathy to be related to Hepatitis A vaccine. Additional information received: This case was reported in a literature article and it described the occurrence of possible vaccine failure in a 3-year-old male patient who had received unspecified hepatitis A immunization (manufacturer unknown). The patient was reported to be healthy prior to the event. He had had a well child check one month prior to evaluation and vaccinations were updated at that time. He had no history of any ingestions, no recent acetaminophen use. No further information on his medical or family history, concurrent condition or concomitant medications was provided. On an unspecified date, the patient received hepatitis A immunization (administration route and site unspecified: dosages unknown; batch number not provided). At an unspecified date, the patient developed jaundice, discolored urine, nausea and itching. Initial labs revealed elevated bilirubin, ammonia and transaminitis in the 4000s. The patient was started on fluids and appropriate medications while workup for transaminitis was initiated, including evaluation for infectious and auto-immune causes. Lab work was negative except for positive Hepatitis A Immunoglobulin M. While work up was being completed the patient had improvement in his transaminases but had worsening liver function. The patient developed severe coagulopathy, requiring frequent blood product transfusions, and worsening encephalopathy. His status continued to worsen and he was listed for liver transplant. This was a serious case as it required hospitalisation. The patient received a liver within days of listing, had an uncomplicated post-operative course and was discharged home three weeks after transplantation with resolution of all symptoms. The outcome of the event was resolved after successful transplantation at the time of reporting. The authors concluded that "vaccination has greatly reduced the number of cases of acute hepatitis A infection. In children that do contract hepatitis A, they rarely develop any symptoms of hepatic dysfunction and less than 5% go on to have fulminant hepatic failure. While hepatitis A is an uncommon cause of fulminant hepatic failure it is a disease that all children with transaminitis should be evaluated for. Hepatitis A spreads quickly and can cause serious liver disease, posing a serious public health risk. This patient had received his hepatitis A immunization and he likely contracted disease before he had developed immunity. For young children with delayed vaccinations it is important to screen for hepatitis A as a potential cause of liver dysfunction".