This study is testing a new COVID-19 vaccine called CVXGA, which is given through the nose, to see if it's safe and how well it works compared to an existing vaccine called COMIRNATY. CVXGA is a vaccine that contains KP.2, and COMIRNATY is a vaccine made using mRNA (a type of genetic material). The study will involve up to 10,016 healthy adults. Participants will be randomly chosen to receive either the CVXGA vaccine or the COMIRNATY vaccine. The study will take about 12 months, and each participant will need to visit the clinic 6-7 times.

Key Points:

• The study lasts about one year with 6-7 clinic visits.
• Participants will receive one nasal dose of CVXGA or one injection of COMIRNATY.
• To join, participants must be healthy adults who have had a previous COVID-19 vaccination at least 6 months prior.