Then this meme and the tweet are complete bullshit as it clearly says mRNA. And inhaled vaccines have existed a long time so again, nothing to worry about.
Discussion
Even if this was a thing, you could just wear an N95.
According to duck.ai, Aerosolized medicine particle size is typically 1-5 microns. N95's are supposed to be good down to 0.3 microns.
mRNA is measured in nano-scale, hance lipid NANOparticles that package them. But its not possible and almost certainly never will so still nothing to worry about