CHARLESTON — West Virginia has some of the strictest limits on exempting children from vaccines required before they can attend school.

But some parents are lobbying the Legislature to change that, while public health officials warn that the state already suffers low immunization rates against diseases such as polio, whooping cough and measles.

All states, including West Virginia, allow school-bound children to skip immunizations for medical reasons. But while 48 states also permit exemptions on religious grounds, West Virginia and Mississippi do not, according to the U.S. Centers for Disease Control and Prevention. Of these other states, 20 also allow philosophical objections including neighboring Ohio and Pennsylvania.

At a House-Senate hearing last month, parents told lawmakers they want a religious exemption in West Virginia. They say they’re wrongly forced to home-school their children, or even enroll them in neighboring states, because they object to the immunization requirements.

“Every parent has the right to make informed, educated decisions regarding their children’s health care, especially in the case of vaccination, which is clearly a medical procedure,” Lori Lee, a leader of this effort, told the Joint Committee on Health.

The parents’ reasons vary. Several speakers alleged a link between vaccines and abortions.

“Fourteen of the vaccines required by the state of West Virginia contain aborted fetal tissue, of over 150 babies, and their cell lines are aging,” Lee told lawmakers. “That bothers me as a Christian, that I have to choose between my faith in God and sending my children to public or private school.”

Public health officials sought to address such concerns during the hearing. Dr. Raheel Khan, assistant professor of pediatrics at West Virginia University, explained how some vaccines have been cultivated in cells that were developed from cells taken from aborted fetuses more than 40 years ago.

“No pregnancies were intentionally terminated to produce these vaccines,” Khan said. “None of these vaccines contain any genetic material from the donor cells.”

Another parent, James Fick, had singled out requiring a preschool vaccine for hepatitis B, an infectious inflammatory disease that infects the liver.

“Hepatitis B is a sexually transmitted disease,” said Fick, an optometrist who practices in Clarksburg and Morgantown. “My toddlers are not at risk to develop a sexually transmitted disease. They are not sharing drug needles. They are not having promiscuous sex.”

But those aren’t the only ways to get that disease, Khan told lawmakers. Most U.S. cases are caused by infected mothers transmitting it to their infants, he said. As it is also transferred through bodily fluids, drooling and biting present risks as well, he said.

Dr. Marian Swinker, West Virginia’s Public Health commissioner, also cited scientific studies debunking alleged links between vaccines and autism, a theory from the 1990s that has been widely discredited. Although sometimes raised by advocates of nonmedical exemptions, the parents and their supporters did not mention this concern during the June hearing.

But several pro-exemption speakers did question whether financial motives explain the growing number of required vaccinations.

“You have to be skeptical of those who are making money on vaccines who are at the same time pushing them,” said Mary Holland, a law professor at New York University who appeared on the parents’ behalf.

Holland urged lawmakers not to view the objecting parents as selfish or free riders. She said that a federal fund has compensated more than 2,500 people for claims arising from vaccine-related deaths or injuries. Vaccines are the right decision for most people, particularly when it comes to basic vaccines that prevent infectious diseases, Holland said, but she also said “the right to prior, free and informed consent to all medical interventions” was a “hallmark of ethical medicine.”

Both Khan and Swinker warned against adding exemptions by citing the state’s low rankings for immunizations. CDC figures from 2011 placed West Virginia 39th for the average vaccination rate for four common immunizations among kindergarten-aged children, nearly 92 percent.

“More liberal laws lead to fewer people immunized, leads to more likelihood of outbreaks,” Swinker told lawmakers.

As for vaccine exemptions, West Virginia was ranked 21st by the CDC for its rate among kindergarteners during the 2009-10 school year, at 1.3 percent. Mississippi had the fewest with a rate of nearly zero while Washington state, which allows both religious and philosophical exemptions, had the highest rate at 6.2 percent.

Swinker argued at the hearing that a direct correlation exists between the rate of non-medical vaccine exemptions and the occurrence of outbreaks. She noted how Washington state officials recently declared a whooping cough epidemic — the first such public health emergency there in at least 13 years.

CDC officials aren’t blaming Washington’s outbreak of whooping cough, or pertussis, on an anti-vaccine movement. But they also say that unvaccinated school-age children in Washington as well as in California, Illinois, Arizona and New York contributed to measles outbreaks in 2008. Those cases offer a better example of the sort of direct correlation cited by Swinker, the CDC’s Dr. Melinda Wharton said.

In the wake of recent outbreaks, Washington state recently tightened its exemption process while California — also known for liberal exemption policies — is considering doing the same. Parents at the June hearing said they are not seeking the sort of philosophical exemptions found in those states.

These supporters of a non-medical exemption argued that compelling vaccinations breeds resentment. But they and the June hearing’s other speakers appeared to agree that education would improve West Virginia’s immunization rate.

“There is a whole body of science and experience that is behind these immunization programs and the vaccines,” Khan said. “Unfortunately, sometimes when the public goes to Google or search these things, the first thing that comes up on their list sometimes are these anti-vaccine things.”