West Virginia, where many families live in rural poverty often far from health care providers, nevertheless has some of the country’s highest vaccine rates for school-age children. Unlike nearly all other states, West Virginia grants exemptions only for medical reasons. The state’s school vaccination law was enacted almost 90 years ago and, despite legislative efforts to change it, remains intact.

West Virginia also has a long libertarian tradition, reflected in the state motto — “Mountaineers Are Always Free” — and a deep strain of social conservatism. Once a Democratic bastion, West Virginia has rocketed to the right over the last 15 years: President Trump twice won it by a margin of more than 40 percentage points.

On few issues do individual liberty and communal obligation flare into direct tension as sharply as they do with compulsory vaccination laws. Across the country, those clashes are becoming more frequent as mandates are rolled back or loosened by Republican lawmakers and officials, often in the name of religious freedom. And just as public health experts have predicted, outbreaks of childhood diseases like measles have risen to rates not seen in decades.

In West Virginia, the conflict over vaccine mandates for children has come to a head in Raleigh County, where lawyers have been battling over the state’s school vaccine mandate. The lawsuits in the county are among several filed around the state since.

Gov. Patrick Morrisey issued an executive order in January directing the state health authorities to grant religious exemptions from the school vaccine mandate. Mr. Morrisey, a Republican in his first year as governor, cited a 2023 state law that provides people with a basis for challenging government actions they believe interfere with their religious beliefs.

But the governor’s order contradicts the school vaccine law, which does not allow for religious exemptions. So the state school board, which has a degree of autonomy under the West Virginia Constitution, has directed county school boards not to accept religious exemptions.

More than 570 such exemptions have been granted by the state health department, many times the number of medical exemptions granted each year. That has prompted the wave of lawsuits over whether religious exemptions are legal — a question that appears bound for the state’s highest court, the West Virginia Supreme Court of Appeals.

But in Raleigh County, a circuit court judge who has heard a challenge involving two local families seems determined to weigh in first. On Wednesday, the judge, Michael Froble, said he was certifying the case before him as a class action that would cover hundreds of families statewide who had requested religious exemptions.

“The parties have argued back and forth as to whether this court can do anything outside of Raleigh County,” Judge Froble said on Wednesday in his courtroom in Beckley, the county seat. “The court believes it can and will.”

The case, which had closing arguments on Thursday, is a thorny one, a consolidation of two lawsuits approaching the vaccine question from opposite sides. In one suit, the plaintiffs want their children to be exempt from vaccines, and in the other suit, the plaintiffs have children with serious medical conditions and want the state to stop granting religious exemptions to any parent who asks.

The state epidemiologist, Shannon McBee, testified in court on Wednesday that any family claiming a religious objection to the childhood vaccines was granted an exemption upon request. No one has been turned down, she said.

Judge Froble has already made a preliminary ruling that the children in the case whose parents have religious exemptions can go to school unvaccinated, a decision that has been appealed to the Supreme Court.

As the hearings unfolded, the courtroom was crowded with lawyers representing a variety of parties in the case — families opposing the mandate, families in favor, an unnamed school employee and the local school board. Different arms of the West Virginia state government are at odds on the question, with lawyers for the state school board arguing against lawyers for the state health department.

Among the lawyers involved is Aaron Siri, a prominent crusader against vaccine mandates and a longtime ally of Robert F. Kennedy Jr., the U.S. health secretary.

Motions have been filed by lawyers on both sides, as well as by the state attorney general, asking the judge to pause the case in Raleigh County until the Supreme Court decides certain fundamental questions. But Judge Froble has rejected these motions.

In a closing argument on Thursday, Chris Wiest, a lawyer based in Kentucky who represents the families seeking religious objections, said he did not contest the assertion that public health is a governmental interest. But under the 2023 religious protection law, he argued, a state action that interfered with a person’s religious belief needed to be “essential” to furthering that governmental interest. A vaccine mandate without religious exemptions, he said, did not meet that test.

“It’s not enough for the defendants to say, ‘Well, geez, we think vaccination is good, we think public health will be furthered by it,’” he said. “They have to show that it’s essential, and that, I think, is one of the areas where we disagree with them.”

Christopher Smith, who represents the state school board, argued that the goal of maintaining public health outweighed the burden felt by religious objectors. “That’s doubly true whenever it’s children in the public school system,” he said. “The vaccine law cannot further its compelling interest, which is promoting things like herd immunity, if there are broad opt-outs.”

Judge Froble initially said he might issue a decision this week but reconsidered and said he would rule in November.