Please assess the completion status of the following clinical trial:

Trial Title: Immune Response of Healthy Subjects Who Received Neonatal Vaccination Course With Engerix™-B Vaccine.

Study Design Characteristics:
- Allocation: NON_RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: PREVENTION
- Time Perspective: None
- Masking: NONE
- Phase: PHASE4
- Number of Arms: 4.0

Eligibility Criteria:
Inclusion Criteria:~* Subjects who the investigator believes that they can and will comply with the requirements of the protocol should be enrolled in the study.~* A male or female who received the complete neonatal primary vaccination course of Engerix™-B in the 103860/273 primary study approximately 20 years earlier.~* Anti-HBs antibody concentrations less than the specified value at the last available follow-up time-point.~* Written informed consent obtained from the subject.~* Healthy subjects as established by medical history and clinical examination before entering into the study.~* If the subject is female, she must be of non-childbearing potential,or if she is of childbearing potential, she must practice adequate contraception for 30 days prior to vaccination, have a negative pregnancy test and continue such precautions for 2 months after completion of the vaccination.~Exclusion Criteria:~* Use of any investigational or non-registered product (drug or vaccine) other than the study vaccine within 30 days preceding the Engerix™-B challenge dose, or planned use during the study period.~* Chronic administration (defined as more than 14 days) of immunosuppressant or other immune-modifying drugs within six months prior to challenge dose administration.~* Planned administration/ administration of a vaccine not foreseen by the study protocol starting from 30 days before the challenge dose and ending 30 days after.~* Administration of a hepatitis B vaccine outside the context of this study between the follow-up time-point at which anti-HBs antibody concentrations was less than the specified value and the current challenge dose study visit.~* 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~* History of allergic disease or reactions likely to be exacerbated by any component of the vaccine.~* Acute disease at the time of enrolment.~* Any confirmed or suspected immunosuppressive or immunodeficient condition, including human immunodeficiency virus (HIV) infection.~* Acute or chronic, clinically significant pulmonary, cardiovascular, hepatic or renal functional abnormality, as determined by physical examination or laboratory screening tests.~* Administration of immunoglobulins and/or any blood products within the three months preceding the challenge dose visit or planned administration during the study period.~* Pregnant or lactating female.~* Female planning to become pregnant or planning to discontinue contraceptive precautions.

- Gender: ALL
- Minimum Age: 19 Years
- Maximum Age: 22 Years
- Healthy Volunteers: t

Study Arms:
- Engerix(4-dose)+HepatitisB(HB) Immunoglobulin (Ig) (Type: EXPERIMENTAL): Subjects who previously received HBV vaccine at 0, 1, 6 and 60 months (4 doses) and HBIg concomitantly at Month 0, and received a challenge dose of HBV vaccine after approximately 20 years (noted as Day 0) in the current study.
- Engerix(3-dose)+HBIg (Type: EXPERIMENTAL): Subjects who previously received HBV vaccine at 0, 1, 6 months (3 doses) and HBIg concomitantly at Month 0, and received a challenge dose of HBV vaccine after approximately 20 years (noted as Day 0) in the current study.
- Engerix(4-dose) (Type: EXPERIMENTAL): Subjects who previously received HBV vaccine at 0, 1, 6 and 60 months (4 doses) and received a challenge dose of HBV vaccine after approximately 20 years (noted as Day 0) in the current study.
- Engerix(3-dose) (Type: EXPERIMENTAL): Subjects who previously received HBV vaccine at 0, 1, 6 months (3 doses) and received a challenge dose of HBV vaccine after approximately 20 years (noted as Day 0) in the current study.

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

Answer: outcome: complete