Proportion of participants with RT-PCR confirmed symptomatic COVID-19 through Day 28. Assessment of safety based on: Incidence of treatment-emergent adverse events. Incidence of solicited injection site reactions through Day 4. Changes from baseline in clinical laboratory tests (i.e., complete blood count with differential and serum chemistry). Changes from baseline in vital signs (body temperature, heart rate, respiration rate, and systolic and diastolic blood pressure).

Proportion of participants with RT-PCR confirmed symptomatic COVID-19 through Day 28. Assessment of safety based on: Incidence of treatment-emergent adverse events. Incidence of solicited injection site reactions through Day 4. Changes from baseline in clinical laboratory tests (i.e., complete blood count with differential and serum chemistry). Changes from baseline in vital signs (body temperature, heart rate, respiration rate, and systolic and diastolic blood pressure).