An international team of researchers from Bristol, Dresden, Munich, Vienna and Denver have successfully completed the first step in the development of an insulin vaccine to prevent type 1 diabetes.
The Pre-POINT study has found a positive immune response in children at risk of type 1 diabetes who were given oral doses of insulin. Adverse reactions such as hypoglycaemia were not observed. The findings, published inJAMA(Journal of the American Medical Association), support the need for a next phase of testing, which will determine whether an insulin vaccine can prevent the outbreak of the disease over the longer term.
Children with type 1 diabetes require several insulin injections every day of their lives. This is because the bodys own immune system destroys the beta cells in the pancreas the cells that produce insulin. This is a process that starts early. Instead of ignoring proteins such as insulin, the immune defences see insulin and other proteins in the cells as foreign and mobilise immune cells to destroy the beta cells. Normally, the immune system develops an immune tolerance to the bodys own proteins during the first years of life, therefore preventing this type of autoimmune response. This tolerance includes the training of immune cells that prevent destruction of the bodys own cells. The aim of the insulin vaccine is to help train this positive preventive immune response.
In the Pre-POINT study, children at high risk of developing type 1 diabetes in Germany, Austria, USA and the UK were treated with oral insulin once daily over periods averaging half a year. The control group was given only a placebo with no effect. The active substance group ingested the insulin in powder form together with food at varying dosage levels that were increased in the course of the study. In the highest dosage (67.5 mg), the insulin powder then induced the desired immune response.