One of the top headlines on USA Today the other day reported mixed results on type 1 diabetes vaccine trials. One of the trials seems very promising — I don't understand all of this, and by the way the article is written I'm not sure the journalist did either, but it sounds like the vaccine essentially turns the patient's T cells into cells that protect beta (insulin-producing cells) instead of attacking them. The drug is in phase 2 trials, and so far so good — although it doesn't prevent diabetes, it looks like it can at least delay the failure of insulin-producing cells.
The article also reports on another trial, one that didn't work. The second trial was also looking for an antigen that would preserve insulin production in diabetics who were just diagnosed. The article says that the antigen works in mice, but not in humans.
What I find curious is that they are only testing these drugs on people who have already been diagnosed. Why? Modern medicine does enable us to identify people who will become diabetic, but aren't yet. For instance, the children of type 1 diabetics are often tested for signs of an autoimmune response, such as elevated T cells. I think it would be much more interesting to test these drugs on people who are destined to be diabetic, and see how long the vaccines would hold off their diagnosis.