A Phase 2b, Randomized, Double-blind, Active-controlled Study of Single Dose CVXGA Intranasal COVID-19 Vaccine in Adults

This is a double-blind, active comparator-controlled Phase 2b study to evaluate the efficacy, immunogenicity, and safety study in which eligible adult participants will be randomized 1:1 to receive CVXGA (CVXGA50) or COMIRNATY. Number of Participants: The proposed enrollment for this study is approximately 434 participants, that includes 16 participants enrolled in Sentinel Cohort 1 and Sentinel Cohort 2 (8 participants in each cohort). Treatment Assignment: Participants in Sentinel Cohort 1 and Sentinel Cohort 2 will be assigned to receive a single dose of CVXGA (CVXGA50) intranasally and will not receive an IM placebo. All other participants in the study will be randomized 1:1 to receive a single dose of CVXGA (CVXGA50) intranasally (plus a single dose of IM placebo), or a single dose of IM COMIRNATY (plus a single dose of intranasal placebo). Study visits: Participants will be asked to complete approximately 6-7 clinic visits, over a period of approximately 12 months duration per participant.