Safety and Immunogenicity of COVI-VAC, a Live Attenuated Vaccine Against COVID-19

This is the first study of COVI-VAC in humans. The purpose of the study is to evaluate the safety and immune response of COVI-VAC (a live attenuated vaccine to prevent COVID-19) in healthy adults aged 18 to 30 years. Approximately 48 participants will be enrolled into 1 of 3 dose groups (low, medium, high). Within each of these dose groups, participants will be assigned randomly to receive either 2 doses of COVI-VAC 28 days apart, 2 doses of placebo (saline), or 1 dose of COVI-VAC and 1 dose of placebo. COVI-VAC or placebo is administered by drops into each nostril. Neither the participants nor the researchers will know whether COVI-VAC or placebo has been received. To assess the safety of the vaccine, each participant will record symptoms and oral temperature in a diary daily for 14 days after each dose. Safety laboratory tests, physical exams, ECGs, and a chest X-ray will also be performed, and peak expiratory flow and vital signs will be measured. Adverse events and medication use will be recorded. Blood samples and intranasal samples will be collected to assess the immune response from the vaccine.