Please assess the completion status of the following clinical trial:

Trial Title: Persistence of Hepatitis B Antibody Levels & Immune Response to a Hepatitis B Vaccine Challenge

Study Design Characteristics:
- Allocation: NON_RANDOMIZED
- Intervention Model: SINGLE_GROUP
- Observational Model: None
- Primary Purpose: PREVENTION
- Time Perspective: None
- Masking: NONE
- Phase: PHASE4
- Number of Arms: 1.0

Eligibility Criteria:
Inclusion Criteria:~* Subjects who the investigator believes that their parents/guardians can and will comply with the requirements of the protocol~* A male or female of 4 to 5 years of age at the time of enrolment.~* With documented evidence of previous vaccination with four consecutive doses of Infanrix hexa™ in Germany.~* Written informed consent obtained from the parents or guardians of the subject at the time of enrolment.~* Healthy subjects as established by medical history and clinical examination before entering into the study.~Exclusion Criteria:~* Concurrently participating in another clinical study, at any time during the study period, in which the subject has been or will be exposed to an investigational or a non-investigational product .~* Evidence of previous hepatitis B booster vaccination since administration of the fourth dose of Infanrix hexa™ booster in the second year of life.~* History of or intercurrent hepatitis B disease.~* Hepatitis B vaccination at birth.~* Planned administration/administration of a vaccine not foreseen by the study protocol during the period starting from 30 days before booster vaccination and ending 30 days after.~* Administration of immunoglobulins and/or any blood products within the three months preceding booster vaccination or planned administration during the study period.~* Chronic administration (defined as more than 14 days) of immunosuppressants or other immune-modifying drugs within six months prior to the HBV vaccine challenge.

- Gender: ALL
- Minimum Age: 4 Years
- Maximum Age: 5 Years
- Healthy Volunteers: t

Study Arms:
- Group A (Type: EXPERIMENTAL): None

Based on this trial design, predict the completion outcome and termination type (if applicable).