Please assess the completion status of the following clinical trial:

Trial Title: Third Dose of Moderna COVID-19 Vaccine in Transplant Recipients

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: PREVENTION
- Time Perspective: None
- Masking: DOUBLE
- Phase: PHASE4
- Number of Arms: 2.0

Eligibility Criteria:
Inclusion Criteria:~* Solid organ transplant recipient who has previously received Moderna vaccine at 0 and 1 months~* Able to provide informed consent~Exclusion Criteria:~* Anaphylaxis or allergic reaction to Moderna vaccine

- Gender: ALL
- Minimum Age: 18 Years
- Maximum Age: None
- Healthy Volunteers: f

Study Arms:
- Experimental group (Type: ACTIVE_COMPARATOR): Participants will receive a one dose of mRNA-1273 vaccine 0.5mL i.m. in deltoid muscle
- Comparator Group (Type: PLACEBO_COMPARATOR): Participants will receive one dose of normal saline injection 0.5mL i.m. in deltoid muscle

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