BirdieBittern

You’re making two common mistakes. First, if you think of a mask’s filtration mechanism as a sieve—where the smaller the particle, the less likely it is to be filtered—you’re wrong. Masks also have an electrostatic mechanism that is very effective at intercepting small particles. So only particles of a middling size (0.1–0.3 µm), for which neither electrostatic capture nor mechanical filtration works particularly well, have a filtration efficiency of only 95%. Larger or smaller particles are filtered more effectively. Second, a single virus particle is very small, but you can't exhale single virus particles. They always exist in the form of droplets or aerosols, and the resulting particles are much larger than a single virus particle.