But - the Antideficiency Act only requires that funds be allocated and appropriated prior to expenditure. That's required to be spread out into monthly allocations. So, funds already allocated and appropriated aren't affected by a shutdown. If NIH is not continuing its medical trials programs, it's because they dropped the ball in their internal budgeting somewhere. Otherwise, they could not be stopped, shutdown or not. (Pre-paid contracts cannot be stopped, either. Only pay-as-they-go contracts get held up.)
Noticed, the history of this thing came about because government agencies, and the military in particular, used to purposely overspend, then go to the Executive branch for more money. Congress created the ADA to keep them from gaming the system, and the Executive from taking unauthorized control of our money. Sounds like a good idea, right? And generally, I'd have to agree. NOT ok for the Prez to just blow and go on our dime. Except that, now the system is getting gamed in a whole new way.
But, it still looks like NIH blew it internally. Otherwise, these patients wouldn't be stopped out.