If I were an evil Communist dictator who for some reason wanted to attack a nation whose bonds I was heavily invested in, and I wanted to use something as arcane as face masks as my delivery vehicle, I would use it as part of a two-step process.
I would treat the masks with human pathogenic fungi spores, like Coccidioides. It's pretty awesome: environmentally available, stable to variable humidity and temperature, effective at low inoculi, dispersible, etc. The wearer breathes the spores in, gets sick and - here's the best part - it impairs his immune system.
THEN I hit them with a respiratory virus simply introduced into the population with unwitting sleeper agents. They mask up, and - spores now deployed - it turbocharges the pandemic!
(I would also have a lair in an inert volcano and a tank full of pet sharks, but that's for another time.)
But a mask contaminated with a virus? Not effective. Not too many of God's creatures(-ish) are as delicate as a virus.
DH
