This case was reported by a nurse via sales rep and described the occurrence of therapy non-responder in a 26-year-old male patient who received ENGERIX B adult). This case was associated with a product complaint. Co-suspect products included ENGERIX B adult, ENGERIX B adult, ENGERIX B adult (batch number 995J5, expiry date 6th February 2017), ENGERIX B adult (batch number F3BB3, expiry date 18th April 2017) and ENGERIX B adult (batch number 24JP3, expiry date 18th July 2017). On an unknown date, the patient received the 1st dose of ENGERIX B adult, the 2nd dose of ENGERIX B adult and the 3rd dose of ENGERIX B adult. On 1st December 2014, the patient received the 4th dose of ENGERIX B adult. On 2nd March 2015, the patient received the 5th dose of ENGERIX B adult. On 10th June 2015, the patient received the 6th dose of ENGERIX B adult. On 1st December 2014, not applicable after receiving ENGERIX B adult, and an unknown time after receiving ENGERIX B adult, the patient experienced extra dose administered. On 2nd March 2015, the patient experienced drug dose administration interval too long and extra dose administered. On 10 June 2015, the patient experienced drug dose administration interval too short and extra dose administered. On 15th September 2015, the patient experienced therapy non-responder. On an unknown date, the patient experienced pharmaceutical product complaint. On an unknown date, the outcome of the therapy non-responder, drug dose administration interval too long, drug dose administration interval too short, extra dose administered, extra dose administered, extra dose administered and pharmaceutical product complaint were unknown. The reporter considered the therapy non-responder to be possibly related to ENGERIX B adult. Additional details were provided as follows: This case was one of the seven reports reported by an occupational nurse for patients tested negative for Hepatitis B following vaccination with ENGERIX B (see cases US2015GSK136757, US2015GSK136758, US2015135763, US2015GSK136759, US2015GSK136761 and US2015GSK136762). The called reported that, they had their laboratory equipment recalibrated and the tests were rerun and results were same or even lower titers. All seven patients were new hires at the company and so the reporter was following them. This case concerned to the patient number 5. The patient was receiving 2nd series of ENGERIX B adult vaccination. On follow up of QA report, there was discrepancy as the reporter stated to have 2nd dose of ENGERIX B adult in the vaccination series. On 1st December 2014, the patient received 4th dose of ENGERIX B adult, which led to an extra dose administered. On 2nd March 2015, the patient received 5th dose of ENGERIX B adult, which led to lengthening of the vaccination schedule and an extra dose administered. On 10th June 2015, the patient received 6th dose of ENGERIX B adult, which led to shortening of the vaccination schedule and an extra dose administered. On 15th September 2015, 97 days after receiving 6th dose of ENGERIX B adult, the patient underwent test for Hepatitis B antibodies and it was found to be negative (quantity 0.2), causing the patient to be a non-responder to the therapy.