I was looking at the packaging of a “Breathe Healthy” face mask I purchased from Amazon (no longer available) over a year ago primarily to use during wildfires. It’s washable and antimicrobial
* Treated with Aegis Microbe Shield®Antimicrobial.
* Lab tested effective @ 1.0 microns. Helps to filter pollens, dust, many types of bacteria, airborne germs from coughs and sneezes, pet dander and mold spores.

The instructions are to hand wash in cold water and air dry. To preserve antimicrobial integrity do not wash in bleach or dry clean.

As I understand, “viruses”, need to hitch a ride on water droplets from sneezes and coughs, so the mask should be effective until the H2O is aerosolized.

That said, filter inserts are available. PM2.5 Activated Carbon Filter for Mask... I was considering using a 27x27 bandana and sewing a pocket to accept these filter inserts, but the masks are available that accept them. Never used them so I have not idea how well they work.