In sanctuaries and retirement facilities, chimpanzees who once contributed to vaccine research are now living under the steady watch of veterinarians and behavioral specialists — not as subjects, but as residents with documented histories and ongoing needs. The institutions that once directed their lives have chosen not to simply close the ledger when the science ended, but to extend their responsibility into the long aftermath. This quiet shift in practice asks a question that echoes across the wider research world: what enduring obligations do we carry toward those whose lives we have shaped