Excitement over a potential preventative treatment for type 1 diabetes reached a high last year as multiple studies showed a link between inoculation with the rotavirus vaccine and a reduced rate of T1D development in children.

These studies came after years of research into the connection between infection with the rotavirus and activation of T-cells against pancreatic cells in those predisposed to type 1.

Due to an increase in the routine administration of the rotavirus vaccine to infants around the world, scientists were finally able to review large scale data on the links between this vaccine and T1D.

But now, despite promising early results, a new study published in March in JAMA Pediatrics shows no link–positive or negative–between this vaccine and the rate of type 1 development.

To understand what this means for the future of type 1 diabetes treatment and prevention, we must take a closer look at the disease’s connection with the rotavirus and the specific studies that have looked at the links between the vaccine and rates of T1D.

The Type 1 Diabetes/Rotavirus Link

It has long been theorized that infection with certain viruses activates beta-cell destruction in people predisposed to type 1 diabetes. One of the viruses most strongly associated with this phenomenon is the rotavirus, which causes millions of cases each year of diarrhea and digestive upset in children under the age of five. 

Mouse studies, including this one published in the Journal of Virology in 2008, show a strong link between rotavirus infection and the acceleration of type 1 diabetes onset.

Even more interesting, many studies have shown a clear correlation between past rotavirus infection and islet cell autoimmunity in children predisposed to type 1. One study, in particular, outlined a significant correlation between rotavirus infection and increased autoantibody load.

It was studies like these that caused many researchers to wonder if the rotavirus vaccine might impact the rates of T1D development.

Encouraging Early Studies on the Rotavirus Vaccine

While some scientists theorized that introducing even a weakened form of the rotavirus to predisposed children might increase the number of T1D diagnoses, others were hopeful that vaccination against the virus might decrease the risk of developing type 1.

Luckily, it was the optimists who seemed to win out as the first papers were published.

In 2019, prominent studies out of both the US and Australia found that the increased rate of rotavirus vaccinations correlated with a decrease in T1D diagnoses in children. The US study even found that getting vaccinated for the virus equated to a 33% reduction in the risk of type 1 diabetes.

The Recent Shift in Perspective

As promising as these initial studies were, there was an inherent flaw in how the data was collected.

In both the US and Australian studies, researchers compared the number of T1D diagnoses before the implementation of routine childhood rotavirus vaccination with the number seen after implementation.

In both countries, the number of children diagnosed with T1D was lower following the widespread use of the vaccine. 

There is no way to determine, however, if this phenomenon was a product of the vaccine or due to some other factor entirely.

While the rate of T1D diagnosis continues to rise, the number of cases in developed countries like the US and Australia has actually begun to plateau over the past couple of decades.

It is very possible that these first studies picked up on the tail end of a trend that was already in progress before the rotavirus vaccine was introduced.

Or, at least, that would seem to be the implication of this most recent study.

Unlike the previous studies, this newer study compared the T1D diagnosis rate of only children born after the implementation of this new vaccination program. The groups were broken down based on whether the children completed the full vaccination series, only part of the series, or remained completely unvaccinated against rotavirus.

In looking at these cohorts, the researchers found that there was no significant difference in the rate of diabetes diagnosis between children who were vaccinated against rotavirus and those who were not.

Finding the Silver Lining

While this most recent study would seem to indicate that the rotavirus vaccine does not protect children from developing T1D, it is still too early to completely count this vaccine out as a potential player in the fight against type 1.

More research and further studies using similar cohort data as this most recent paper will be needed before any true conclusion can be drawn.

In the meantime, there is a silver lining to this most recent information. 

While the vaccine failed to demonstrate any apparent protection against the development of T1D in the children studied, it did not appear to increase the risk of developing T1D either.

This is important to note considering, early on, many scientists thought that the rotavirus vaccine may pose a risk to children predisposed to type 1 diabetes.

For now, all of us T1D parents can breathe a sigh of relief knowing that while the RV vaccine may not be doing any extra good for our children, it is, at least, not doing any extra harm.