A nasal spray vaccine may prevent type 1 diabetes from developing in humans, early trial results show.
Type 1 diabetics usually rely on daily insulin injections to normalise their ability to break down glucose, a vital function needed to supply energy to the body. Diabetics are unable to produce insulin on their own because their overzealous immune systems kill off the beta cells that produce the hormone.
As part of a global trial underway in Australia, New Zealand and soon Germany, researchers in Melbourne found a nasal spray vaccine desensitised the immune system, thereby stopping it from attacking the beta cells that produce insulin naturally.
“These latest results encourage us that we are on the right track to finding a vaccine for type 1 diabetes,” said Professor Len Harrison from the Walter and Eliza Hall Institute’s Immunology division, who conducted the trial jointly with Professor Peter Colman and Dr Spiros Fourlanos from the Royal Melbourne Hospital.
The study, which was published in the journal Diabetes, involved 52 adult type 1 diabetics who were at the early stages of the disease and did not yet require daily injections. Some participants took the nasal spray and some took a placebo every week for 12 months.
Those who took the spray soon found that their immune systems no longer attacked the insulin-producing cells with the same ferocity and, when injected with the hormone, were found to be desensitised to it.
The medicine was administered by nasal spray to prevent it being digested in the gut, which would happen if it was consumed orally.
Professor Harrison said the early tests were exciting not just for diabetics, but for sufferers of other health problems too.
“The nasal vaccine approach, if shown to be successful in human type 1 diabetes, could also be tested with different vaccines for the prevention of other autoimmune diseases such as rheumatoid arthritis and multiple sclerosis,” he said.
The trial began in 2006 and is now halfway through the testing phase. It is sponsored by Melbourne Health and is funded by the National Health and Medical Research Council and the Juvenile Diabetes Research Foundation, through the Diabetes Vaccine Development Centre in Sydney.
More information about the trial can be found at www.stopdiabetes.com.au.