“a substance”
Again, too sloppy and non-specific. A bullet is a substance made of lead which can also stop a virus.
Which definition would you like to use?
proust wrote: “Again, too sloppy and non-specific. A bullet is a substance made of lead which can also stop a virus”
The fact that you don’t like the definition doesn’t change the fact that it is the accepted definition of a virus. Of course, it is convenient for the anti-vaxxers to have their own definition of a virus. That way they can claim anything that doesn’t fit their definition isn’t a vaccine which is rubbish.