Their results showed that the process of vomiting actually caused some of the virus to aerosolize, or form a fine suspension in the air, which would allow it to travel airborne.
In the case of marijuana, the active component THC is aerosolized and follows the same pathway into your body, but with different effects which we explain in our video" Your Brain on Marijuana" here.
It can be spread by vomiting and because it can aerosolize to some extent, people can pick up enough that way, it can be spread through the stool if you accidentally get a little bit of feces on something.