I'm thinking perhaps nano-particles. Whatever it is, it's not good.
Someone from a sophisticated lab with the right equipment needs to analyze them.

Way up in the nose is the Cribriform Plate, a thin, delicate, porous bone that separates the nose from the brain. They could possibly implant something there like nanoparticles from the PCR swab. Also, if schools want to do that twice a week, they could likely punch through the delicate bone and puncture the brain!

I'm thinking perhaps nano-particles. Whatever it is, it's not good.
Someone from a sophisticated lab with the right equipment needs to analyze them.