June 14, 2019
Researchers studying the effectiveness of the rotavirus vaccine have found a surprising association with diabetes.
Infants who received full doses of the so-called "stomach flu" vaccine in their first six months of life have a lower risk of developing Type 1 diabetes, a chronic condition without a known cure, according to a University of Michigan study published in the journal Scientific Reports.
Researchers found that children who received all recommended rotavirus vaccine doses were 33 percent less likely to develop Type 1 diabetes. But they stressed their findings only reveal an association. They have not proven a causal relationship.
"This is an uncommon condition, so it takes large amounts of data to see any trends across a population," epidemiologist Mary A.M. Rogers said in a statement. "It will take more time and analyses to confirm these findings. But we do see a decline in Type 1 diabetes in young children after the rotavirus vaccine was introduced."
Rogers said researchers will know more about the relationship in five years, because the first groups of U.S. children to receive the modern rotavirus vaccine are now in grade school, the period when Type 1 diabetes is most often detected.
Earlier this year, a study of Australian children found a 14 percent reduced risk of Type 1 diabetes after the rotavirus vaccine was introduced.
Type 1 diabetes is caused by an autoimmune reaction that kills pancreatic cells that produce insulin, according to the U.S. Centers for Disease Control and Prevention. It can take years before enough cells are destroyed before symptoms appear. Left untreated, the condition is deadly.
Unlike Type 2 diabetes, diet and lifestyle habits do not cause the Type 1 disease.
The Michigan researchers examined anonymous insurance data from 1.5 million American children born both before and after 2006. That's the year the modern rotavirus was introduced in the United States.
They compared data from 540,000 children who received the full rotavirus vaccine series – all born after 2006 – and nearly 547,000 children who were born prior to the vaccine's availability.
They also analyzed data from nearly 141,000 children who received at least one rotavirus vaccine. Children who did not complete the series also had a lower risk of developing Type 1 diabetes.
As for their original undertaking, the researchers found the rotavirus vaccine greatly reduces a baby's chance of ending up in the hospital due to rotavirus.
Rotavirus causes diarrhea and vomiting that can last 3 to 8 days, according to the CDC. Children also may experience fever or abdominal pain.
The study was funded by the National Institutes of Health.