To be clear, I was just merely trying to track back where this '100%' claim was coming from as I also didn't remember such a bold claim being ever made, let alone by Fauci.
Now, I invite you to make google searches with a date range and you will see that such studies claiming 100% efficacy on the product on kids started to appear in the early days actually:
Since 100% is a pretty awesome figure, my theory is that there must have been quite a bit of press coverage at the time and I have no doubt a lot of people got confused.
Also that press release is not by any possible definition from “early days” nor is it issued by Dr Fauci.