A measles, mumps and rubella vaccine. (Mike Hutmacher/Wichita Eagle via AP)

A leading autism advocacy organization, Autism Speaks, is urging parents to vaccinate their children amid a measles outbreak that has swept 14 states.

As some continue to cite unfounded fears that vaccinations can lead to autism, Autism Speaks chief science officer Rob Ring has released a statement saying vaccinations cannot cause the disorder — and telling parents to vaccinate their children.

“Over the last two decades, extensive research has asked whether there is any link between childhood vaccinations and autism,” he said late last week in a brief statement. “The results of this research are clear: Vaccines do not cause autism. We urge that all children be fully vaccinated.”

Autism Speaks, a nonprofit organization that promotes autism awareness and sponsors research in the field, has stated its policy on vaccinations before, but perhaps never so plainly as now. In the past, the organization, which funded research into possible connections between immunizations and autism, has said it is possible that, in rare cases, “immunization may trigger the onset of autism symptoms in a child with an underlying medical or genetic condition” — while pointing out that “studies have not found a link between vaccines and autism.”

Fears about vaccination were bolstered by a bogus study that claimed to show a link between the measles, mumps and rubella (MMR) vaccine and autism. The now-discredited study was published in 1998 by British doctor Andrew Wakefield in an esteemed medical journal, the Lancet. The journal later retracted the study, and Wakefield lost his medical license. But his research is still touted as true by some who refuse to vaccinate.

In 2011, Autism Speaks was one of the sponsors of a National Autism Association event at which Wakefield was a speaker. Nevertheless, over the years, the organization has made its policy on the immunization issue clear: Vaccinate your kids. For example, in May 2014, Autism Speaks linked to a report on its Web site that showed vaccinations do not cause autism.

“This analysis provides further confirmation for a lack of association between vaccines and autism that the broader health-care community has understood and embraced for some time,” Ring said last year about the findings. “Autism Speaks’ own policy on vaccines echoes those of other credible health-care organizations like the American Academy of Pediatrics and the World Health Organization. We strongly encourage parents to work with their physician to ensure their children receive the full benefits immunization offers in protecting their loved ones against a variety of preventable childhood diseases.”

The organization was not immediately available for comment.

All states permit parents to choose not to vaccinate children for legitimate medical reasons such as anaphylactic allergic response, a life-threatening reaction. And many allow them to opt-out for religious or personal beliefs. But non-medical exemptions have come under scrutiny since a measles outbreak in California’s Disneyland swept the country. Last month, 102 people from 14 states were reported to be infected, according to the Centers for Disease Control and Prevention.

Since then, doctors have spoken out about the anti-vaccine movement. Some have refused to see patients who refuse their immunizations. Los Angeles pediatrician Charles Goodman posted a notice in his waiting room last month: He would no longer treat children whose parents won’t get them vaccinated.

“Parents who choose not to give measles shots, they’re not just putting their kids at risk, but they’re also putting other kids at risk — especially kids in my waiting room,” he said, according to the Associated Press.

Medical experts have said those who are not vaccinated pose a risk to those who cannot be vaccinated because they have legitimate medical reasons or because they are too young. Children cannot get their MMR vaccine until they are 12 months old.

Harry Gewanter, a doctor in Richmond, said it’s parents’ responsibility to vaccinate.

“I’ve seen the horror stories of what happens from these diseases and now this generation of doctors have never seen them because of immunization practices,” he said, according to WWBT-TV. “One out of a thousand people infected with measles dies. And just because we haven’t seen it doesn’t mean it’s not coming.”

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