ABOVE: Rotavirus and type 1 diabetes may trigger immune system responses that attack insulin-producing cells in the pancreas in similar ways.

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A recent decrease in the incidence of type 1 diabetes in Australian children may be linked to the introduction of a routine vaccine against rotavirus, according to a study published yesterday (January 22) in JAMA Pediatrics. Using observational data, researchers in Melbourne found that diabetes rates have been declining in infants since the vaccine’s launch in Australia in 2007—a finding that dovetails with previous research hinting that rotavirus infection is a risk factor for the autoimmune disorder.

“While not conclusive, our latest study suggests that preventing rotavirus infection in Australian infants by vaccination may also reduce their risk of type 1 diabetes,” study coauthor Len Harrison of the Walter and Eliza Hall Institute says in a statement.

The team reports that, having increased steadily since the 1980s, the number of type 1 diabetes cases among children under four years old has been falling since 2007 when the oral rotavirus vaccine was folded into the Australian National Immunisation Program, according to the press release.

Based on his and others’ research, Harrison suggests the association might be the result of the way in which both conditions activate the immune system. “Twenty years ago our team revealed an association between the appearance of immune markers of type 1 diabetes in children and rotavirus infection,” Harrison says in the statement. “Subsequent studies in laboratory models suggested rotavirus infection of pancreatic cells can trigger an immune attack against the insulin-producing cells—similar to what occurs in type 1 diabetes.”

Federico Martinon-Torres, a researcher at Hospital Clínico Universitario de Santiago and Instituto de Investigacion Sanitaria de Santiago in Spain who was not involved in the work, notes in an email to Reuters that the findings add to existing evidence of connections between viral infections and autoimmune disorders in general.

“Rotavirus have been associated with an increased incidence of celiac disease and type 1 diabetes,” he says. “Inflammatory response against rotavirus in early stages of immune maturation is associated with tolerance breakdown and immune dysregulation.”

The Australian team now plans to explore the association in a more controlled study, with results expected later this year.