We aren't completely safe about anything in this world, including all the viruses that we currently have in our society. I think that we will just learn how to live with it, as we did before with other diseases.
Where do all the viruses come from... the millions of them floating around in the air?
They are rogue exosomes, expelled from the bodies of people... except for the ones like Covid, that doctors and researchers create.
Or do you know better?
They must be smart and full of energy. Floating about at temperature changes, at all altitudes, humidity, somehow deal with atmospheric pressure changes and varying dew points, don't crash-land...
They ARE smart. For example, the smartsat doctors, researchers, and scientists in the world, can barely create or start anything that might be considered a living being of some sort. But nature manufactures millions of varieties of life, and they reproduce by the millions. Nature is billions of times smarter than the smartest people.