This mucosal/nasal vaccine is called MPV/S-2P and it is developed by the NIH's National Institute of Allergy and Infectious Diseases (NIAID). From a 2023 study:

A single dose of MPV/S-2P was highly immunogenic, and a second dose increased the magnitude and breadth of the mucosal and systemic anti-S antibody responses and increased levels of dimeric anti-S IgA in the airways.

Obviously don't dox yourself on Hexbear, but the phase 1 trial sites are:

so if you live near one of those, maybe you can participate.

They want to enroll 60 people, no clue how close they are to that goal

To try to enroll, contact them by phone or email.