Rotavirus Vaccines Trigger Diabetes

Applied Genetics News, August, 2000

Infection with rotavirus, the commonest cause of gastro-enteritis in children, may lead to childhood diabetes. Australian researchers led by Margo Honeyman of the Walter and Eliza Hall Institute of Medical Research (Melbourne, Australia) discovered the link after a 6-year study of 54 babies. . All had a parent or sibling with type I diabetes and so were at risk of developing the disease. The study raises the question of whether rotavirus vaccines may trigger the same reactions.

As expected, all the children followed by Honeyman's team became infected with rotaviruses during the study. In the 24 children who showed clear signs that they were developing diabetes, levels of antibodies in their blood that signal an attack on the pancreas went up almost every time they got a rotavirus infection. The antibodies then dropped until the next infection. Children who didn't develop diabetes showed no signs of their pancreas being attacked following a rotavirus infection. Neither did the rotavirus trigger an increase in antibodies against any other organs.

How the virus might trigger diabetes isn't yet clear. It may damage cells in the pancreas directly when it infects them. Alternatively, it might mimic the pancreatic proteins that incite the immune system to attack. If mimicry is the answer, it could spell trouble for some of the rotavirus vaccines being developed. The hope is that these vaccines will save the lives of thousands of children in poor countries who die from gastro-enteritis each year. But the tamed virus in some vaccines might also trigger diabetes in susceptible children.

"It's fairly convincing evidence that rotavirus might be one of the triggers for juvenile onset diabetes," comments virologist David Cubitt of the Great Ormond Street Hospital in London. "The idea of molecular mimicry is extremely interesting, but obviously lots of other bits of the puzzle need to be put in."

By trying to infect mouse pancreatic cells in culture, Honeyman hopes to confirm whether, and how, rotavirus damages the pancreas. Honeyman has not excluded the possibility that other viruses are involved. Coxsackie B is suspected.