Please assess the completion status of the following clinical trial:

Trial Title: A Trial Evaluating the Safety and Effects of an RNA Vaccine ARCT-021 in Healthy Adults

Study Design Characteristics:
- Allocation: RANDOMIZED
- Intervention Model: PARALLEL
- Observational Model: None
- Primary Purpose: PREVENTION
- Time Perspective: None
- Masking: QUADRUPLE
- Phase: PHASE2
- Number of Arms: 8.0

Eligibility Criteria:
Inclusion Criteria:~Individuals who:~1. are able to provide consent~2. agree to comply with all study visits and procedures~3. are willing and able to adhere to study restrictions~4. are sexually active and willing to adhere to contraceptive requirements~5. are male or female ≥18 or (in Singapore) ≥21 years of age~6. are medically stable~Exclusion Criteria:~Individuals who:~1. have had SARS-CoV-2 infection or COVID-19 disease.~2. have had cancer except for cancers that were treated and that have low risk of returning~3. have chronic kidney disease~4. have some chronic lung diseases~5. have some heart conditions~6. have compromised immune systems~7. are obese~8. have sickle cell disease or some other blood disorders~9. are current smokers and/or use illegal drugs~10. have Type 2 diabetics~11. are immunocompromised, immunodeficient or have had a transplant~12. have autoimmune disease~13. have other severe or uncontrolled diseases or disease that may interfere with the interpretation of the study~14. have a positive test for hepatitis B or C or human immunodeficiency virus~15. have had a severe reaction to previous investigational vaccines~16. have a fever or are feeling sick close to the time of the first vaccination of the study~17. have positive drug test at screening~18. are pregnant~19. are breastfeeding~20. have a bleeding disorder~21. have previously received an investigational coronavirus vaccine (SARS-CoV(1) or MERS) or who plan to be in other COVID-19 studies~22. have recently been vaccinated with other vaccines~23. have recently received blood products~24. who work at one of the clinic sites participating in this study, work at Arcturus, who work at other companies that monitor the study or close family members to the sites, Arcturus, or partners involved in study monitoring~25. other restrictions may apply

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

Study Arms:
- Study Group 1, Younger Adult Participants (Type: EXPERIMENTAL): Participants will receive one dose of ARCT-021 on Day 0, one dose of Placebo (saline) on Day 28 and on Day 208 either one dose of ARCT-021 or one dose of placebo
- Study Group 2, Younger Adult Participants (Type: EXPERIMENTAL): Participants will receive one dose of ARCT-021 on Day 0, a second dose of ARCT-021 on Day 28 and on Day 208 either one dose of ARCT-021 or one dose of placebo
- Study Group 3, Younger Adult Participants (Type: EXPERIMENTAL): Participants will receive one dose of ARCT-021 on Day 0, a second dose of ARCT-021 on Day 28 and on Day 208 either one dose of ARCT-021 or one dose of placebo
- Study Group 4, Younger Adult Participants (Type: PLACEBO_COMPARATOR): Participants will receive one of Placebo (Saline) on Day 0, one dose of Placebo on Day 28, and one dose of Placebo on Day 208
- Study Group 1, Older Adult Participants (Type: EXPERIMENTAL): Participants will receive one dose of ARCT-021 on Day 0, one dose of Placebo (saline) on Day 28 and on Day 208 either one dose of ARCT-021 or one dose of placebo
- Study Group 2, Older Adult Participants (Type: EXPERIMENTAL): Participants will receive one dose of ARCT-021 on Day 0, a second dose of ARCT-021 on Day 28 and on Day 208 either one dose of ARCT-021 or one dose of placebo
- Study Group 3, Older Adult Participants (Type: EXPERIMENTAL): Participants will receive one dose of ARCT-021 on Day 0, a second dose of ARCT-021 on Day 28 and on Day 208 either one dose of ARCT-021 or one dose of placebo
- Study Group 4, Older Adult Participants (Type: PLACEBO_COMPARATOR): Participants will receive one dose of Placebo (saline) on Day 0, a second dose of Placebo on Day 28 and a third dose of Placebo on Day 208

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