The child was behind on her vaccinations. Wendy Sue Swanson took note of this as she talked with the girl’s parents last week at a medical clinic in Mill Creek, Wash., outside Seattle.

Swanson, like many pediatricians, sometimes needed to coax parents to get the shots for their children. A few might be unmovable in their objections. But most were like this couple: A mom and dad who might harbor doubts or were just behind schedule. They were at least willing to listen.

Now, Swanson had a new way to prod parents like them: Discussing the Disney measles outbreak in California, which has spread to at least 68 people in 11 states since Jan. 1 and raised alarms about the reemergence of a disease once considered all but vanquished. There was something powerful about the disease hitting a popular, recognizable vacation spot.

The girl got her vaccination. Her parents were on board.

“Their eagerness was different,” Swanson said later. “I think it is changing people.”

Much of the scrutiny in the Disney measles outbreak has fallen on an entrenched anti-vaccination movement in places such as Orange County, Calif., home to the two Disney theme parks where the outbreak gained its foothold. These “anti-vaxxers” are viewed as dead-set against vaccinations.

But doctors believe the current outbreak could change the minds of a less-known but even larger group: parents who remain on the fence about the shots. These “vaccine-hesitant” parents have some doubt about vaccinations, leading them to question or skip some shots, stagger their delivery or delay them beyond the recommended schedule. An estimated 5 to 11 percent of U.S. parents have skipped at least one vaccination or delayed a shot, according to studies. That compares to only 1 to 3 percent of parents who object to all vaccinations.

Boosting compliance among the “vaccine hesitant” population could have major public health implications, doctors say, especially because last year the United States had its highest number of measles cases since 1977. The topic of “vaccine hesitant” patients has become the focus of a growing body of medical research in recent years. Doctors are trying to understand what triggers vaccine worries and which strategies work best for overcoming those fears.

Doctors spend many office hours trying to convince these parents that the scientific evidence proves the shots are, in fact, safe and effective. But these hesitant parents have been bombarded by conflicting information. And they don’t view all of the shots the same way. The vaccine to protect against measles, mumps and rubella faces particularly strong resistance as a result of thoroughly discredited studies linking the vaccine to autism. So some parents, even those generally open to other vaccines, push to delay or skip this one. The shot is supposed to be given at 12 months and again at age 4.

“One of the problems that vaccines face now is they work too well,” said Michael Smith, a pediatric infectious disease specialist at the University of Louisville School of Medicine in Kentucky, who has studied vaccine-hesitant parents.

Parents don’t have experience with measles, how children can become very ill and in rare cases suffer brain swelling or even die, Smith said. At the same time, these parents are confronted with stories about the unexplained rise in the U.S. autism rate.

“I can understand as a parent why you’d skip the vaccine if you’d been convinced that it’s a choice between giving my kids a shot or giving my kid autism,” Smith said.

But the Disney outbreak changes the discussion. Now, doctors have an event to point to. The threat is no longer abstract or distant.

“This is definitely going to be a talking point that pediatricians should keep in their back pockets,” Smith said.

Studies have shown that “anti-vaxxer” parents are likely to remain steadfast in their opposition. Barbara Loe Fisher, president of the National Vaccine Information Center, a group that raises doubts about the shots, said she was not convinced that the Disney outbreak was even a story about the dangers of being unvaccinated.

“I don’t think we know completely what’s going on,” Fisher said.

But physicians such as Kathryn Edwards of the Vanderbilt Vaccine Research Program said the measles vaccine is at least 99 percent effective after the second dose. And measles is one of the most communicable diseases, much more so than the flu. The dangers posed by the disease have been forgotten. Many U.S. doctors have never even seen it. Edwards still recalls the only patient she ever saw with measles, years ago when she was a medical resident. He died.

“So I have a lot of respect for measles,” Edwards said.

At Boston Children’s Hospital, pediatrician Claire McCarthy said she is always happy when parents decide to vaccinate their children against measles in particular. She worries about the current situation in California. And she plans to use the Disney outbreak to try to convince hesitant parents that vaccinations are the right choice.

“I am planning on talking this one up a lot with families,” McCarthy said. “I think this probably will make a difference.”