Is this really a good idea? In the US, live replicating vaccines like smallpox, unattenuated adenovirus, Ebola, etc. already have problems with post vaccination shedding and infecting the administrating health care worker even when used in very controlled environments. The live polio vaccine was stopped from the use in the US due to shedding. I guess this could be used in military boot camp where everyone except the recruits puts on gas masks and the whole room gets filled with LNP/mRNA aerosol, but even that's a bit dubious re. consistent dosing.