The referenced study https://www.nature.com/articles/s41551-023-01086-2 says "a mouse model" and "non-human primates":

"We show that pGal–antigen therapy induces antigen-specific tolerance in a mouse model...as well as the suppression of antigen-specific responses to vaccination against a DNA-based simian immunodeficiency virus in non-human primates"

The article also mentions that phase I trials have been carried out with humans:

"initial phase I safety trials have already been carried out in people with celiac disease...and phase I safety trials are underway in multiple sclerosis"

Thanks! I didn't think to search for "phase" despite that being an obvious term when wondering about trials.

As someone with Crohn's and Ankylosing Spondylitis, that phase 1 trials had me excited in a long time. I did not take TNF blockers because of the cost and side effects.