With the surge of Delta, my work is testing ALL employees before returning to work. Of course, we don't all come in on a daily basis - 99% of my crew work 14 days on 14 days off, so they get tested once a month before going to work.
This is what DoA has to do before he goes to work each hitch. He is sent a PCR test which he has to do DIY style and get sent off within 7 days of when he reports back to work (when they first started doing that, he had to make a telemed appt so the medical professional could watch him do it and be sure it was done correctly) and then he has to do a quick test at the heliport when he gets there. This has been the protocol for them since the tests came out last year. They have also been wearing masks all the time, indoors or outdoors, in all common areas except the dining hall. Some have been fully vaxxed, but so far they have not made it mandatory.
In spite of all these folks having to do that, there have been some cases that have popped positive after they get to work. Those are banished to their quarters until they can be sent home (usually a day or two) and those who share a room or work closely together are also made to quarantine on board until they get sent home.