“It was awful and it didn’t have to happen because I could have had them vaccinated. I felt guilty, I felt really guilty,” she told ABC News.

O’Meara, a teacher living outside Chicago, added that she had “scoured everything” about why vaccines might be harmful and had become “pretty convinced.” She chose not to vaccinate based upon the results of her research, but had only read the materials that cast doubt.

“I put my kids at risk,” she said. “I wish that I had taken more time to research from both sides before my children were born.”

Her three children — all under the age of seven — are now fully vaccinated after an aggressive regimen to bring them up to date on recommended shots.