Lawmakers in the General Assembly have put to bed a two-year fight to boost the state's last-in-the-nation track record on immunizations.

A final compromise on Senate Bill 163, which formalizes the state's requirements on immunizations, was hammered out by a conference committee Saturday.

The House adopted the amendments, crafted by a conference committee, on a near-unanimous vote, but it didn't result in any votes from the Republican side, and it passed on a party-line 41-24 vote. The Senate Saturday night also adopted the report and re-passed the bill on a 20-13 vote.

"This is an important time to improve our immunization rates," said Democratic Sen. Julie Gonzales of Denver, who sponsored the bill along with Republican Sen. Kevin Priola of Henderson.

Senate Bill 163 is intended to boost Colorado's immunization rates. It continues to allow exemptions based on religious beliefs, medical reasons or personal beliefs.

It does, however, require parents who seek those exemptions for their children to either obtain a certification of medical exemption from a health care provider, sign a certificate for a non-medical exemption, or show proof they're completed an online education module offered by the state department of public health.

The measure also requires schools to publish their immunization rates. 

The immunization bill, and another in 2019, have drawn hundreds of anti-vaccination opponents to the Capitol as well as filibusters from House Republicans. Anti-vaccination opponents have incorrectly stated the bill would require their children to be vaccinated in order to attend public schools.

Sen. Owen Hill, a Colorado Springs Republican, in advocating against the bill, said the decision on immunizations should rest with parents.

"It is our job ... to tell parents, what's the best way to protect the health of their children, and nobody cares about the health of children more than their parents." This bill takes an approach that the state knows best, Hill said.

Priola told the Senate the bill "gives the power to the parent to make the decision to opt-out" or follow through with educators and schools so that other children have an opportunity to be educated in a safe manner.

As amended by the conference committee, the bill gives broad latitude to home-schooled students, including those who attend private schools part-time. Those students who would be exempted from the bill unless the private school requires those immunizations. 

As a nod to opponents, House Democrats added an amendment allowing a petition clause that could put the issue in front of voters in 2022. But the conference committee took the petition clause out.

The bill now heads to the governor, who is expected to sign it.

According to the Centers for Disease Control and Prevention, the nationwide average of kindergartners who received their measles, mumps and rubella vaccines for the 2018-19 school year was 94.2%.

Colorado's rate was 87.4%, the worst in the nation. The percentage of students who have received the diphtheria, tetanus, and whooping cough vaccine, nationwide is 94.6%; Colorado, at 90.3%, puts the state 49th out of 50.

SB 163 sets a goal of 95% for the measles vaccine.

Colorado last had a measles outbreak last December. It's not only a public health concern; it's also a expensive one: the CDC reported in 2017 the public health cost to contain two unrelated cases in 2016 was more than $68,000.

This story is from Colorado Politics, a statewide political and public policy news journal. Used by permission. For more, visit coloradopolitics.com.