Germs only and after 15-20 minutes of use they are totally ineffective as the pores expand, laden with the moisture from one's breath.
They know that it's just for show.
Since you mentioned the VA I will share this experience with you.
At the height of covid hysteria I escorted my father to the VA for an appointment. As he required a wheelchair for long distances, I fetched him one and rolled him in. We were stopped at the door and were told that no visitors where allowed further, patients only.
I unzipped my jacket and held it open revealing the red t-shirt I was wearing underneath that said in bold white lettering,
"SERVICE ANIMAL".
The doorman and I looked each other in the eye for a long moment before I stated, "humans are animals, are we good?"
Another long moment later the doorman nodded his head in the affirmative and stepped aside.
There's more...
They came to the waiting room to call him to the treatment area and I followed the staff member there, pushing the old man in the chair.
The nurse asked how I got in the building and I opened my jacket displaying my shirt and said, "if a canine can be a service animal surely a human can".
Her eyebrows raised, she shrugged, and went about her business.
But wait, there's even more!
When she left the room for a moment, dad tapped my shoulder, and with a sly grin pointed a bony, shaking finger which my eyes followed to see a sign posted at the door to the room.
It read, NO SERVICE ANIMALS BEYOND THIS POINT.
😄