A Phase 2 Trial to Evaluate Safety and Immunogenicity of a Next-generation COVID-19 Vaccine Delivered by Inhaled Aerosol to Humans
The goal of this clinical trial is to study the safety of a new inhaled vaccine to prevent COVID infection and learn about the immune responses that are made in the lungs and the blood after vaccination. Participants will be randomized (like the toss of a coin) to receive the experimental vaccine or a placebo (a look-alike solution that contains no vaccine). To be in the study participants will have to have already had three doses of a messenger ribonucleic acid (mRNA) COVID vaccine and be generally healthy. Participants are given a single dose of the vaccine by breathing in a fine mist that goes directly into the lungs. During follow-up participants will: * visit the clinic for checkups and blood tests at 2, 4 and 8 weeks after vaccination * report their symptoms for 24 weeks after getting the vaccine. In some participants, the researchers will collect cells from the lung 4 weeks after vaccination (a test known as a bronchoscopy).
• Adults who are 18-65 years old on the day of randomization (day 1)
• Able to read, write and communicate using the English or French language.
• Received at least 3 doses of an mRNA COVID vaccine.
• Individuals of childbearing potential must have a negative pregnancy test prior to vaccination and be willing to practice effective contraception for 8 weeks post-vaccination.
• Able to understand and comply with protocol requirements and instructions; able to report adverse events; able to attend scheduled study visits and complete required investigations.
• For participants in the BAL sub-study, Complete Blood Count (CBC) and chemistry (creatinine) within normal limits.
• For participants in the BAL sub-study, forced expiratory volume in 1 second (FEV1) \> the lower limit of normal (LLN), and FEV1/FVC (forced expiratory volume in 1 second/forced vital capacity) ratio above the LLN.
• Agree not to enroll in any other intervention studies for the duration of the study where the intervention could be reasonably expected to be associated with adverse events overlapping with the inhaled vaccine or the immune responses being measured.