As far as I am concerned, either Dr. Fauci wanted people to vaccinate or not. In the former case, saying that his welfare would be improved by people vaccinating is merely restating that same thing. This is the only meaning in which an economist would use the word "welfare": it is certainly the meaning in which it is used in the model we are talking about.

Once again, in terms of the model we are talking about, if you say that Dr. Fauci´s welfare would not be improved by people vaccinating, you are merely saying that he did not want people to vaccinate. Is that what you are claiming?