I can start with that. That's a very good question.
Viral vector vaccines do have a place, but every vector is not identical. There are a range of.... There's vesicular stomatitis, adenovirus, and there are different types of adenoviruses. I don't think we can put them all in the same bucket. They may not all have the same efficacy or safety concerns.
Therefore, at this point, I wouldn't honestly say that they are done, at all. That they—