By Shaun Boyd

DENVER (CBS4) – Colorado’s low vaccination rate is once again the subject of legislation at the state capitol.

This time the debate is over who should keep track of kids’ immunization records.

The state health department has an immunization tracking system, but because it’s voluntary the state doesn’t know who’s vaccinated and who isn’t. Rep. Dan Pabon says it should.

“When Colorado is still at the bottom of the barrel when it comes to the number of children vaccinated, we have to address this as a public health issue,” said Pabon, a Democrat who represents northwest Denver.

Right now, parents are required to notify schools if they choose not to vaccinate their kids and the schools reports percentages to the state. Legislation introduced by Pabon would require parents to notify the health department instead.

“This takes the burden off school districts — we are already giving them enough to do — and putting it where it should belong, which is in the public health department,” he said.

But Theresa Wrangham, head of the National Vaccine Information Center, says the state simply wants the names of addresses of kids who are vaccinated.

“I think this is about another way to harass parents who choose to delay or decline (vaccinations),” she said.

Wrangham says the bill violates a federal law protecting the privacy of student records.

“Parents have an expectation of privacy around students’ school records that is guaranteed under federal law and basically what this does is rewrite the law to say the essential information now goes directly to the department of health and will be uploaded into the immunization information system, which doesn’t keep you private anymore,” Wragham said.

Pabon says state law requires the information to be kept confidential and he says parents can opt out of their kids records going into the immunization information system.

“This is some of the most sensitive data the government can collect so we’re absolutely positive that this information is going to be kept confidential. There will only be aggregate data, if any, that’s reported about the vaccination rates in Colorado,” he said.

Pabon says the bill is aimed at making it easier for the health department to protect kids most at risk when there’s an outbreak.

“We saw whooping cough last year chicken pox this year. Who knows what’s next. These are all preventable diseases.”

But Wrangham says the state can already find the children if there’s an outbreak.

“If there was some sort of emergency where they really did need that individual identifying information, the law already provides for that,” she said.

Two years ago, lawmakers tried to pass a bill that would have made it more difficult to opt children out of vaccines. It failed amid much controversy. The new bill is also contentious. It will get its first hearing in the House Public Health Care and Human Services Committee on Feb. 25.

Shaun Boyd is CBS4’s political specialist. She’s a veteran reporter with more than 25 years of experience. Follow her on Twitter @cbs4shaun.