That depends, and the question is not complete.
1) they could approval and EUA, and they test it on folks with long haul covid
2) They can open up the existing data, and then go out and collect the history in tested people to see if those that took Bucilamine, avoided Long haul covid versus placebos, before or after the FDA EUA approval is issued
3) They could modify the trial, and add Long haul covid people, if the FDA allows that sort of thing, but that gets complicated....
4) The could get the EUA approval for covid and then run clinical trials on Long Haul covid, with out a phase 3, if it is already approved for covid.
Lots and lots options....