TULSA, Oklahoma - Things got heated Thursday night during a discussion about whether or not to vaccinate children.

A Tulsa doctor, who questions vaccinations, took on a state senator and his bill, which could change who's required to be vaccinated.

There was plenty of yelling, and State Senator Ervin Yen could barely get a word out at times because many in the crowd were vehemently against his support of vaccinations.

For psychiatrist Stephanie Christner, the debate over whether to vaccinate is personal.

"I had an infant daughter who was born perfectly healthy, and at two months of age I was really undecided, so I just said to the pediatrician, 'Okay,' she said. “From that day forward, she just declined."

Christner said a medical examiner determined her daughter died of SIDs, but she said her daughter's deterioration began after being vaccinated.

"They're infant babies. You really don't know how one baby is going to react to another," Christner said.

Thursday, she went head to head Yen, a cardiac anesthesiologist and state senator.

Christner told the crowd there is evidence vaccines can cause disabilities and be deadly; but, the government, and Yen, insists complications from vaccines are rare.

Yen is proposing a bill that would restrict families, in public and private schools, from opting out of vaccinations for religious or personal reasons.

"I'm all for parental rights. I'm all for less government. But when you have children dying, like the 50-day-old in Elk City, we've got to do something," he said.

Yen says science doesn't lie.

Take, for instance, measles, which the Centers for Disease Control said were all but eradicated, but this year, the CDC said 189 Americans have gotten it.

Many in the crowd weren't swayed.

One person said, "What constitutional authority do you have, in the country I served, to tell me what I can or can't put in my children's bloodstream?"

The group who made up the majority of the crowd at the meeting is Oklahomans for Vaccine Choice.