Once again, news about a communicable disease in Washington state should catch the eye of Oregon lawmakers when they meet next year. They should end the state’s immunization exemption for religious grounds.

The latest outbreak is measles, that highly contagious disease that used to be a normal part of childhood. A single case turned up in a Woodland, Wash., primary school last week and because they’re unvaccinated, at least 25 children have been sent home for two weeks or until they’ve been immunized against the disease. This summer it was whooping cough, which reached epidemic proportions with more than 4,400 infected in Washington state.

That didn’t have to happen. But there’s a trick to making vaccines effective, something called the herd effect. It works this way: If 80 percent or so of kids are vaccinated against a disease, it’s unlikely that illness will make inroads into a school. When the number falls below 80 percent, as is becoming increasingly common, all bets are off.

In Bend, more and more children are at risk as herd immunity dwindles. The Bulletin’s health reporter, Markian Hawryluk, reported last year that immunization rates at four schools in the city were well below that magic 80 percent number.

We’d buy the idea that parents whose religious beliefs discourage immunization have a right to forgo vaccines for their children but for one thing.

For some kids, the decision not to vaccinate has nothing to do with religious tenets and everything to do with compromised immune systems. When kids who cannot receive vaccines for health reasons are in a region or school with low immunization rates, they are put at risk through no fault of their own.

While Americans have a beloved constitutional right to practice — or not practice — their religions as they see fit, there is a caveat, as is the case with other First Amendment freedoms. That right is sacred only as long as it doesn’t put others at risk. If it does, compromises must be made.

It’s time for one of those compromises in Oregon, and in Washington, for that matter. Immunization against measles, whooping cough, polio and other diseases is required because the infections do put people at risk, and we cannot let one family’s religious convictions endanger the child next door.