Please assess the completion status of the following clinical trial:

Trial Title: Safety and Efficacy of COVID-19 Prime-boost Vaccine in Bahrain

Study Design Characteristics:
- Allocation: None
- Intervention Model: None
- Observational Model: ECOLOGIC_OR_COMMUNITY
- Primary Purpose: None
- Time Perspective: CROSS_SECTIONAL
- Masking: None
- Phase: None
- Number of Arms: None

Eligibility Criteria:
Inclusion Criteria:~* Adults aged ≥21yo.~* Asymptomatic 24h before the administration of booster dose.~* Has no active or previous RT-PCR lab-confirmed COVID-19 diagnosis.~* Completed three months to six months after the second dose of BBIBP-CorV.~* Have at least one Antibody test done before receiving the BBIBP-CorV booster dose OR can be done if the participant is yet to receive the BNT162b2 booster dose.~* Tested negative using Rapid Antigen Detection Test on the day of receiving the booster (positive results will confirm with RT-PCR).~* Study participants must have the ability to give informed consent.~Exclusion Criteria:~* Children aged \<21yo.~* Symptomatic within 24h before the administration of booster dose.~* Has active or previous RT-PCR lab-confirmed COVID-19 diagnosis.~* Did not complete three months to six months after the second dose of BBIBP-CorV.~* Does not have at least one Antibody test done before receiving the BBIBP-CorV booster dose~* Tested positive using Rapid Antigen Detection Test on the day of receiving the booster (positive results will be confirmed with PCR).~* Patients unable to give informed consent.

- Gender: ALL
- Minimum Age: 21 Years
- Maximum Age: None
- Healthy Volunteers: None

Study Arms:
- Homologous booster (Type: None): Two doses of BBIBP-CorV, followed by BBIBP-CorV
- Heterologous booster (Type: None): Two doses of BBIBP-CorV, followed by BNT162b2

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