This is a book that I read within the past 5 years or so, but it was quite a bit older I think. Probably from the 1980's or even earlier.
I can't remember the cover. I think there were mulitple main characters and you switched viewpoints.
The people had gone from earth and were living inside the comet or asteroid to do research and possibly mining too.
Somehow there was a disease that started to spread, and so the people from earth wouldn't let the people on the comet come back and the book ended with them heading out of the solar system.
You're welcome. "Heart of the Comet" has all the elements you mentioned (research and mining on a comet, multiple viewpoint characters, disease and quarrantine), so it almost has to be it.
I can't remember the cover. I think there were mulitple main characters and you switched viewpoints.
The people had gone from earth and were living inside the comet or asteroid to do research and possibly mining too.
Somehow there was a disease that started to spread, and so the people from earth wouldn't let the people on the comet come back and the book ended with them heading out of the solar system.