Rosemary tea is the best answer I have found, and it is excellent.
You can see the full, original discussion at the link below .
In my case we had 10 people in a house and one person got novovirus. By the time they were vomiting, I assumed we all had it.
The reason you vomit is because the virus creates serotonin as a toxin (yeah, the body produces and uses it, just not in the gut, and at those levels). The stomach reacts to the increased serotonin levels by getting everything out at all costs. Vomiting, diarrhea, etc. Forceful and repeated.
I am not sure what the Rosemary tea does, but once 4 of our entourage were in full swing, I found the anecdotal information and dug through a rather huge stash of dried herbs that we have (I used to sell dried herbs... another story). Sure enough, I had some OLD dried Rosemary, and we simply added it to boiling water, about a tablespoon to a pint.
We all (even the vomiting people) drank that tea like a religion for the next 24 hours. It seemed to work well. Those that had not yet started vomiting never did. They just needed some extra sleep. As an aside, we were also taking diatomaceous earth, Liposomal C, and water with Hydrogen Peroxide (20 drops to a pint), but the Rosemary tea seemed to be more effective as reducing symptoms that all the others combined.