I really would like to know if Vitalik Buterin has invested here in eHealth too

Would be really amazing!
HA! everybody would like that , but don't hold your breath. even if he was, it wouldn't be public.
I bet he doesn't like it that his fame is used to create a hype about a project so it makes sense for him to be quiet about most of his investments.
It would be awesome idea but not unless he decide to gladly promote the project, we can only hope for the best to come.

Would be awesome if they would announce a partnership/investment from him after the private round closes. Would give the project the next big step

That would be wonderful, and after private round finishes and ico starts, i cant imagine the hype around in this project. We'll see about that.