Dr. Lawrence Steinman, a professor of pediatrics and neurological sciences at the Stanford University School of Medicine, said the finding suggested the vaccine selectively countered the errant immune response that causes type 1 diabetes.
The multicenter, randomized, double-blind trial found levels of a blood-borne proxy of insulin production was maintained -- and in some cases increased -- over the course of the 12-week dosing regimen.
This finding indicated those getting the vaccine might have suffered less ongoing destruction of beta cells, which produce and secrete the peptide -- short protein sequence -- hormone insulin after a meal, than those given placebo injections.
The blood levels of a specific group of immune cells that inappropriately homed in on and destroyed a protein found only on beta cells appeared to have been selectively depleted in patients receiving the vaccine. No adverse effects, serious or otherwise, that could be attributed to the vaccine were observed, Steinman said.
"We're very excited by these results, which suggest that the immunologist's dream of shutting down just a single subset of dysfunctional immune cells without wrecking the whole immune system may be attainable," Steinman said in a statement.
"This vaccine is a new concept. It's shutting off a specific immune response, rather than turning on specific immune responses as conventional vaccines for, say, influenza or polio aim to do."
The findings were published in the journal Science Translational Medicine.