Safety and Immunogenicity Trial of MPV/S-2P SARS-CoV-2 Vaccine in Adults

A phase I clinical trial to evaluate the safety, reactogenicity, and immunogenicity of MPV/S-2P administered intranasally to adults who have previously received a primary series and at least one booster with an authorized or licensed mRNA SARS-CoV-2 parenteral vaccine. The study is designed as a non-randomized, open-label, dose-escalation clinical trial in non-pregnant adult participants, 18-64 years of age (with a goal of 30 percent or more \>/=50 years of age), with or without prior SARS-CoV-2 infection, who are in good health and meet all other eligibility criteria. For the evaluation of three doses of MPV/S-2P vaccine, a sample size of 60 participants is anticipated. To evaluate for early safety signals vaccination will proceed in a staged fashion. For Cohort 1, three sentinel participants under 50 years of age will be enrolled over at least 2 days. A safety review of clinical data and virologic shedding data through at least Day 8 will be conducted by the Safety Review Committee (SRC) prior to enrollment of the remainder of the cohort. Once Cohort 1 is fully enrolled, progression to Cohort 2 will be based on evaluation of halting rules, and cumulative clinical safety and virologic shedding data from Cohort 1 through at least Day 8 by the SRC. Cohort 2 and 3 enrollment and safety oversight will proceed in the same fashion as Cohort 1. At the discretion of the SRC, additional participants in the cohort may be designated sentinels for any cohort. If halting rules are met the study will be paused for the SRC safety data review. The primary objective is to evaluate the safety and reactogenicity of a single dose of MPV/S-2P in previously vaccinated healthy adults. The secondary objectives are 1) To evaluate the systemic anti-Spike humoral immune responses after vaccination 2) To evaluate nasal mucosal IgA and IgG responses after vaccination 3) To assess the duration and magnitude of viral vector (vaccine) shedding 4) To assess the immune response towards the vector.