The vaccine that prevents rotavirus, which can cause severe gastric problems in children, may have another benefit: lowering the risk for Type 1 diabetes in toddlers.

Rotavirus can leave children badly dehydrated and is sometimes fatal. Fortunately, there are two vaccines for the disease, easily administered by putting drops in the child’s mouth at ages 2 months, 4 months and (for one version of the vaccine) 6 months. Both vaccines are more than 90 percent effective.

An Australian study, published in JAMA Pediatrics, examined the prevalence of Type 1 diabetes in the eight years before and after the rotavirus vaccine came into use in 2007. They found that in children up to 4 years old, born after the introduction of the vaccine, the rate of Type 1 diabetes decreased by 14 percent in the years following the vaccine’s introduction. In children older than 5, there was no difference in rates of rotavirus before and after the use of the vaccine.

The lead author, Kirsten P. Perrett of the University of Melbourne, said that these results, while not conclusive, show that it is possible that preventing rotavirus will reduce the risk for Type 1 diabetes in some infants at genetic risk. “The takeaway message is: Vaccinate!”