received a dose of Engerix on / 29Jul2020, 26Aug2020, and 23Dec2020. She is not seroconverting / titer testing / 26-FEB-2021; Drug dose interval too short; This case was reported by a nurse via call center representative and described the occurrence of therapy non-responder in a 24-year-old female patient who received HBV (Engerix B) (batch number L5C49, expiry date 17th May 2022) for prophylaxis.   Co-suspect products included hepatitis B vaccine pre-filled syringe device (Engerix B Pre-Filled Syringe Device) injection syringe for prophylaxis, HBV (Engerix B) (batch number L5C49, expiry date 17th May 2022) for prophylaxis, hepatitis B vaccine pre-filled syringe device (Engerix B Pre-Filled Syringe Device) injection syringe for prophylaxis, HBV (Engerix B) (batch number H2T35, expiry date 29th May 2022) for prophylaxis and hepatitis B vaccine pre-filled syringe device (Engerix B Pre-Filled Syringe Device) injection syringe for prophylaxis.   Previously administered products included Engerix B (1st dose received on November 2019), Engerix B (2nd dose received on December 2019), Engerix B with an associated reaction of therapy non-responder (3rd dose received on 25th May 2020, refer case:US2021AMR060235) and Hepatitis B VACCINE with an associated reaction of therapy non-responder (received 3 doses of hepatitis B in 1996 refer case: US2021059726).   On 23rd December 2020, the patient received the 3rd dose of Engerix B and Engerix B Pre-Filled Syringe Device. On 26th August 2020, the patient received the 2nd dose of Engerix B and Engerix B Pre-Filled Syringe Device. On 29th July 2020, the patient received the 1st dose of Engerix B and Engerix B Pre-Filled Syringe Device. On 23rd December 2020, unknown after receiving Engerix B and Engerix B Pre-Filled Syringe Device, not applicable after receiving Engerix B, Engerix B Pre-Filled Syringe Device, Engerix B and Engerix B Pre-Filled Syringe Device and not applicable after receiving Engerix B, Engerix B Pre-Filled Syringe Device, Engerix B and Engerix B Pre-Filled Syringe Device, the patient experienced drug dose administration interval too short. On 26th February 2021, the patient experienced therapy non-responder. On an unknown date, the outcome of the therapy non-responder and drug dose administration interval too short were unknown.   This report is made by GSK without prejudice and does not imply any admission or liability for the incident or its consequences.  Additional details were reported as follows: On 20th November 2019, the titer was tested, and the patient was found to be not converting. Since the patient was not converting, she then received 3 doses of Engerix B.  On 20th July 2020, the titer was again tested, and the patient was found to be not seroconverting The patient then received 2 doses of Engerix B and the last dose earlier then recommended scheduled, which led to shortening of vaccination schedule. On 26th February 2021, the titer was again tested, and the patient was found to be not seroconverting. The reporter consented to follow-up. Due to argus behavior precise TTO was reflecting for event drug dose interval too short.; Sender's Comments:  US-GLAXOSMITHKLINE-US2021AMR060235:same reporter US-GLAXOSMITHKLINE-US2021059726:same reporter