A Phase 1, First-In-Human Study of the Investigational COVID-19 Vaccine SC-Ad6-1 in Healthy Volunteers

Key Inclusion Criteria: * Adult males and females, 18 to 60 years of age (inclusive) * Body mass index ≥ 18.0 and ≤ 32.0 kg/m2, with a body weight ≥ 50 kg at screening * Must have been fully vaccinated against COVID-19 and received last dose not less than 3 months prior to Day 1 (High Dose #3 I.M. and I.N. booster arms only), not less than 5 months prior to Day 1 (High Dose #4 I.N. booster arm only) and not less than 12 months prior to Day 1 (I.H. booster arms and I.N or I.H. multiple dose booster arms only) Key Exclusion Criteria: * History or presence of significant cardiovascular, pulmonary, hepatic, renal, haematological, gastrointestinal, endocrine, immunologic, dermatologic or neurological disease * History of chronic respiratory disorders including asthma, emphysema, interstitial lung disease, pulmonary hypertension, recurrent pneumonia, or recent (≤14 days prior to Screening) or ongoing respiratory tract infection * History of thrombosis (e.g., deep vein thrombosis, pulmonary embolism, etc.), any coagulation dysregulation disorder, or a history of thrombosis noted in immediate family members * History of any neurological disorders or seizures including Guillain-Barre syndrome, with the exception of febrile seizures during childhood * Known previous infection with SARS-CoV-2 or presence of antibodies against SARS-CoV-2 or a positive SARS-CoV-2 PCR test (non-booster arms only) * Any history of malignant disease ≤5 years prior to registration * History of clinically relevant immunosuppression from, but not limited to, immunodeficiency conditions such as common variable hypogammaglobulinemia