I think it's called infectious agent or something close to that.
I'm not an expert, but medicine's are drugs, created to help people, in certain ways, such as Adderall helping with ADHD or Elderberry. But drugs that aren't medicine are like cocaine that might've been used for medicinal uses back in the day, but now is just used for personal use, such as weed, it can be considered medicinal but it's used more for pleasure than to help a illness
Corona is actually a word derived meaning “crown”. It is used in different places for different meanings. For example, if you have watched the movie “Tangled”, you will find that Rapunzel was a long lost princess of the kingdom of Corona.