CHICAGO (WPVI) --One Chicago mom's three children are happy, healthy and now fully vaccinated - but it wasn't always that way.
Kristen O'Meara is a teacher and a mom of three and until recently, she was a big believer in anti-vaccination research.
"I scoured everything I could possibly find about why vaccines might be harmful. I became pretty convinced," she recalled.
So she chose not to vaccinate her children. But then, her 5-year-old and 3-year-old twins were stricken with a case of rotavirus.
Kristen and her husband also got very ill.
With the whole house sick, she started rethinking those vaccines.
"It was awful and it didn't have to happen because I could have had them vaccinated. I felt guilty, I felt really guilty," said Kristen.
Although the American Academy of Pediatrics recommends vaccinations for practically every child, the group says that the number of parents refusing to vaccinate their children may be on the rise.
In 2013, 87 percent of pediatricians surveyed had encountered parents who refused to vaccine, which was up from 76 percent in 2006.
Some parents cited they believed vaccinations were unnecessary and they had concerns about autism, a link which has repeatedly been disproven.
"I put my kids at risk. I wish that I had taken more time to research from both sides before my children were born," said Kristen.
Today, Kristen's children are fully up to date on their vaccinations after an aggressive catch-up regimen.
She says she hopes her story will encourage others to take a second look.