A vaccine for type 1 diabetes has shown enough promise during a small clinical trial to excite the research team who ran the study. It's a reverse vaccine, one that works the opposite way most conventional vaccines do.
Stanford University School of Medicine researchers produced a DNA-based vaccine that turns off the portion of the immune system that controls the destruction of insulin-producing cells in the pancreas, according to Medical News Today. The findings appeared in the journal Science Translational Medicine.
All 80 patients in the trial were type-1 diabetics who received insulin injections. The National Diabetes Information Clearinghouse states that diabetes affects nearly 26 million U.S. residents, including an estimated 7 million who are undiagnosed. Of those diagnosed, around 5 percent have type 1.
According to the Mayo Clinic, type 1 diabetes was originally called insulin-dependent or juvenile diabetes. It occurs when the immune system kills beta cells in the pancreas. Betas are the only cells that produce insulin, a hormone necessary to regulate blood levels of glucose. Type-1 diabetics must receive supplemental insulin to survive.
Scientists consider the new vaccine a reverse product because it shuts down the body's immune response instead of boosting it as traditional vaccines do. The vaccine targets an individual component of the immune system while sparing the rest.
Knowing that certain immune system cells hunt for cells with unhealthy or suspicious proteins on their surface, the Stanford team wondered why these hunter cells attack the beta cells that produce insulin. To reduce the attacks, they created a vaccine that contained DNA from the gene that coded for the protein the hunter cells were seeking. In essence, the researchers developed a vaccine that causes the patient's immune system to attack the part of itself that destroys beta cells.
One group of trial subjects received weekly placebo injections for 12 weeks. The other four groups received different doses of vaccine that contained modified genetic material in the DNA used.
At the end of the trial, the researchers opted to measure subjects' levels of C-peptide, which is a piece of proinsulin, a precursor protein for insulin. Since C-peptide remains in the blood a lot longer than insulin, experts consider it the better indicator of insulin production. The team concluded that since C-peptide levels were maintained and sometimes increased during the trial, fewer beta cells were destroyed in subjects who received the vaccine instead of the placebo. In addition, the number of cells hunting the beta cells dropped in patients on the vaccine.
Benefits appeared to wane a few weeks after the last vaccine injection. The findings noted no serious side effects from the trial.
The Stanford researchers acknowledge the need for larger, longer-lasting trials using the reverse DNA vaccine. They stress that it could be years before approval of a vaccine for type 1 diabetes in humans.
Vonda J. Sines has published thousands of print and online health and medical articles. She specializes in diseases and other conditions that affect the quality of life.
- Pharmaceuticals & Drug Trials
- type 1 diabetes
- immune system