This clinical trial investigates two different types of COVID-19 vaccines as booster doses in healthy adults. The study compares a new intranasal vaccine called LVT-001, which is given as a nasal spray, with Comirnaty JN.1, which is an injectable mRNA vaccine. The intranasal vaccine contains proteins from the virus that causes COVID-19, while Comirnaty JN.1 contains genetic material that helps the body produce protective proteins.
The main purpose of this study is to evaluate the safety of different doses of the intranasal vaccine and compare how well both vaccines stimulate immune responses in the nose and bloodstream. The study is divided into two parts. In the first phase, researchers will test three different strengths of the nasal vaccine. In the second phase, they will compare the nasal vaccine to the injectable mRNA vaccine.
During the study, participants will receive one booster dose of either the nasal or injectable vaccine. They will be monitored for any side effects and will provide nose swabs and blood samples to measure their immune response. The monitoring period will continue for one year after vaccination. Researchers will also track whether participants develop SARS-CoV-2 infections during this time.
France 
