I once interviewed three mothers who were convinced that they had poisoned their children. They all reported seeing a change following an injection of a measles, mumps and rubella vaccine. The kids’ eyes had lost their sparkle, the mothers said, their speech stopped developing and they started engaging in strange behavior like flapping their arms and spinning.

The diagnosis was autism, and the mothers were convinced that a preservative in the vaccine was to blame. They were plaintiffs in what was going to be a massive class action lawsuit that would get the pharmaceutical companies to pay for what they had done, just like the tobacco companies had been forced to pay.

I remember being moved by these mothers. (What parent hasn’t felt guilty when their child suffers?) But the lawsuit did not go anywhere, and the research on which it was based has been thoroughly debunked – not just as incorrect, but also as “an elaborate fraud,” according to the medical journal in which it was published.

Instead of the issue being put to rest, however, it has only picked up steam. The number of parents who are convinced that their children are better off without immunization is on the rise, especially here in Maine, where 5.2 percent of kindergartners started the year without being vaccinated.

The evidence of the benefits of universal vaccination is overwhelming to everyone except the people who need to be convinced. Organized groups of vaccine alarmists can produce studies that support their point of view: So can climate deniers and tobacco lobbyists. And they are right that a parent has to accept some risk of a serious reaction when allowing their child to get a shot, but it’s less than 1 out of 1 million doses of the MMR vaccine, according to the federal Centers for Disease Control and Prevention.

It’s a risk smaller than the risk they take driving to the doctor’s office. And the chance of catching and dying from the disease is exponentially higher without the vaccination than with it.

What’s happening here is a far-reaching cultural shift. It involves a loss of faith in institutions, like government, medicine and the media. It is facilitated by information technology that allows people to speak only to others they agree with and assemble their own set of facts. And it is fed by fear.

Now it’s also getting political.

Once made up of a fringe of people on the far left and far right, the vaccine refuseniks are going mainstream in the 2016 presidential campaign. Some Republican contenders are trying to walk a fine line, offering general support for vaccines while suggesting that their use should be voluntary.

New Jersey Gov. Chris Christie was first, saying that parents should have a “measure of choice” when it comes to vaccination. Kentucky Sen. Rand Paul said, “I have heard of many tragic cases of walking, talking normal children who wound up with profound mental disorders after vaccines.”

And Texas Sen. Ted Cruz said he chose to have his children vaccinated, but that whether vaccines should be mandatory is a question for the states.

Clearly, these men are all reading the same polls, but their lack of leadership is appalling.

This is not some phony controversy that has no life beyond the campaign. If people choose to believe that Barack Obama was born in Kenya or that the moon landing was faked, they aren’t hurting anyone but themselves. But vaccines are different.

It is not, as the candidates seem to believe, just a matter of personal choice.

Not everyone can get vaccinated. Newborns can’t. People with compromised immune systems can’t either.

Their lives depend on making cases of communicable diseases are as rare as possible. And when families refuse to vaccinate, they are putting those lives at risk.

Vaccine opponents – like Katherine Paul of Freeport, who wrote a column published in this paper Tuesday – say they are not “anti-vaccine,” but object to the way the government regulates the pharmaceutical industry. Opting out “is a tool to pressure those entities to thoroughly study and report on the safety of these drugs for all children, not just most children,” she said.

What should we expect politicians to say about people who are willing to take risks with their neighbors’ health as a “tool to pressure”? It’s not what we have heard from them so far.

Anecdotal tales of children who may have been damaged by vaccines are heartbreaking, but they cannot be allowed to outweigh conclusive scientific proof that vaccines are one of the greatest life-saving inventions in history.

Science, not anecdotes, should rule here. And political leaders should not be afraid to tell the truth.

Greg Kesich is the editorial page editor. He can be contacted at 791-6481 or at:

gkesich@pressherald.com

Twitter: gregkesich