Looking at Wikipedia (which reads like it was written by a PR person) he seems fairly qualified to talk about viruses
https://en.wikipedia.org/wiki/William_A._Haseltine#HIV/AIDS_...
Infection prevention or preventing severe symptoms, are however part of the secondary endpoints of the trials, something that it is not mentioned in the article.
For a counter argument, see https://mobile.twitter.com/nataliexdean/status/1308474303810...