Yea, if you just see to the direct effects that's fairly obviously the way it is and you shouldn't take the retrovirus. The main way in which taking the virus would be a good thing is if you're the only person willing to test it and that it'll be used for a lot of good on others if you're willing to test it but not get further if you don't. I have no idea why my brain picked that very non-standard situation as the default previously.
Link: abcnews.go.com/Health/friendly-extreme-meet-kids-adults-williams-syndrome/