After several hours of testimony from parents and doctors, Colorado’s House Health, Insurance and Environment Committee passed a bipartisan measure Thursday night aimed at making it harder for parents to send their children to school without receiving required vaccines.

Under current Colorado law, parents are able to opt out of vaccinating their children with a statement of exemption for religious or personal beliefs.

Sparked by recent whooping cough outbreaks, HB 14-1288 would require parents opposed to vaccination to complete an online education module and acquire the signature of a health care professional confirming disclosure of possible health risks "to the student and the community.”

State Rep. Dan Pabon (D) proposed the bill to ensure that parents are more informed and "that they're not just opting out simply because of convenience," according to the Denver Post.

"Vaccine refusal results in higher rates of vaccine-preventable disease," Pabon said. "This is a public health issue. These are very serious diseases."

Colorado has the sixth-highest rate of non-vaccinated public school kindergarteners. The bill will also mandate all licensed schools and day care centers to release public records on the percentages of their non-vaccinated children.

"There are kids who can't get vaccinated because they're immuno-compromised and are being exposed to vaccine-preventable diseases,” Pabon argued on Thursday. “To add on top of that, older populations that have medical conditions are also at risk."

Although the bill would not eliminate the personal belief exemption, parents opposing the legislation argued that increased education mandates could lead to the erosion of parental rights during Thursday’s testimony before lawmakers.

"Parents have a constitutional right to parent their children," Susan Lawson, whose daughter developed encephalitis after a routine vaccine when she was a year old, told CBS Denver. "I am not an uneducated woman."

Anti-vaccination advocacy group National Vaccine Information Center has also attacked the proposal as one that “singles out and discriminates against a minority of parents with sincerely held personal beliefs … by assuming they are uneducated and should be forced into a state approved ‘education’ program.”

Between 2009 and 2012, 18 states introduced 36 immunization exemption bills, five of which sought to make obtaining vaccination exemptions more difficult. Three of them -- in Washington, California and Vermont -- became law, according to a study by Emory University's School of Public Health. A similar law in Oregon on non-medical exemptions also went into effect on March 1.