Vaccine May Prevent Type 1 DiabetesElizabeth Nelson
There’s a great deal of controversy surrounding vaccines these days, and many people are declining to vaccinate their children for fear that certain vaccines may cause autism or other health problems. But as this storm of disagreement continues, another ray of sunshine is coming through the clouds in favor of vaccines.
In Australia, the rate of type 1 diabetes diagnoses, which has been increasing steadily since 1980, is beginning to slow, and experts believe a particular vaccine may have something to do with it. It’s not a diabetes vaccine, though. Australia is known for having a particularly rigorous vaccination program, but they haven’t found a vaccine for diabetes just yet. No, this vaccine is something completely different: the rotavirus vaccine.
The rotavirus vaccine was introduced in two oral forms in 2007 and administered to babies between two and four months of age. The vaccine was meant to protect against the rotavirus, a terrible infection that was the leading cause of severe and potentially life-threatening diarrhea. Over the course of time, the vaccine has likely saved millions of lives, and it has prevented thousands of hospitalizations every year. But it may be benefitting us in another way as well.
New research is showing that the oral rotavirus vaccine may have a pleasant, albeit accidental, side effect. Shortly after the introduction of the rotavirus vaccine in mainstream medicine, Australian researchers saw the number of new cases of type 1 diabetes begin to decrease. The rate of type 1 diabetes cases in children aged zero to four dropped by 14 percent.
“The significant decrease… wasn’t seen in older children aged 5-14,” explains lead author Kirsten Perrett, of the University of Melbourne. “This suggests the young children could have been exposed to a protective factor that didn’t impact older children.”
Because only very young children were affected by this positive effect, it was reasoned that they had been exposed to something new that hadn’t affected other children. That’s when they realized the rotavirus vaccine was likely to be involved.
Some researchers, however, had a hunch that the rotavirus was connected to diabetes long before this evidence surfaced. They noticed almost two decades ago that the immune markers in type 1 diabetes looked very similar to those in the rotavirus and guessed that there must be some connection between the two.
The rotavirus vaccine is not believed to actually prevent type 1 diabetes, but it is thought that contracting the rotavirus may be a risk factor for developing diabetes, because the infection appears to trigger an immune attack on insulin-producing pancreatic cells. Protecting against the rotavirus, therefore, may also lend a small helping hand in keeping children from getting type 1 diabetes.
“While not conclusive, our latest study suggests that preventing rotavirus infection in Australian infants by vaccination might also reduce the risk of type 1 diabetes in some infants at genetic risk,” says senior author Len Harrison, also of the University of Melbourne.
Around the world, type 1 diabetes rates continue to increase. Australia is one of the only places where they appear to be turning around, suggesting that the Land Down Under is onto something that the rest of us are missing. However, there is one little problem. A similar study in Finland with a smaller sample size and time frame was unable to find similar results to this one, suggesting that genetic and environmental differences between groups of people may play a role in how well the rotavirus vaccine works to prevent type 1 diabetes.
“At this stage, we don’t yet know whether the reduction in type 1 diabetes is a permanent effect, or transient, and it may only be relevant to Australian children,” says Harrison.
But for now, Australia continues to research the phenomenon in the hopes of learning more about type 1 diabetes and enabling us to prevent it more often in the future.