Intentional non-vaccination is causing avoidable public health disasters in the United States. The problem is particularly acute for measles — though similar things might be said for flu and other diseases -- because measles is so efficiently transmitted from one susceptible person to another.

Measles herd immunity requires more than 90 percent of Americans to be immunized. This daunting number may understate the challenge, since small communities that are ambivalent about immunization provide local pockets of vulnerability within which local outbreaks can take hold and spread.

It’s all-too-easy to see how these issues could become enmeshed in the culture wars, partisan politics or even the 2016 presidential campaign. This would be a public health disaster. We will never sustain herd immunity if Americans’ beliefs and behaviors in the realm of vaccination harden along cultural or religious or ideological lines.

Ambivalence about vaccines crosses conventional political boundaries. People of varying backgrounds and views find powerful reasons to doubt medical and public health authority, to distrust Big Pharma. These doubts and distrust don’t come from nowhere, and are deeply-held—which is why so many pro-vaccination messages often fall short. Many others simply wish to free-ride on the herd immunity provided by others.

We must continue to debunk false rumors about vaccines—most prominently the debunked theories that that the MMR vaccine causes autism. We must recognize, however, that providing and repeating credible medical information only accomplishes so much. The required information has been out there for many years, available in two minutes to anyone with access to Google.

It's not just the message that matters. To reach the people we most need to persuade, the messenger matters, too. There is and long has been ample evidence for the safety of common vaccines. Repeating this message only accomplishes so much with intentional non-vaccinators.

So here’s what President Obama, Presidents Jimmy Carter, George HW Bush, Bill Clinton, George W. Bush, Majority Leader McConnell, Governor Mitt Romney, Senator Bernie Sanders, House Speaker Boehner, Senator Rand Paul, Dr. Ben Carson, Governor Bobby Jindal,  Senator John McCain, and others should do.

They should get together on the White House lawn. Maybe better yet, we need one of those YouTube viral videos:

In whatever form, our political leaders must dramatically convey a simple, utterly nonpartisan message that cuts through the clutter to makes five points:

  1. We have many deep divisions over every political issue you can imagine. We have no disagreement on the basic issues of vaccination.
  2. We are vaccinated ourselves, and we have vaccinated our children.
  3. Vaccines are safe and effective. They can protect you and your family against measles, flu, and other preventable diseases.
  4. Vaccines are essential to protect our loved-ones, friends, and neighbors who often can't be immunized and who are especially vulnerable to these diseases. Some are cancer patients. Others have diseases of their immune systems. Still others are infants or seniors who can die of these readily-preventable diseases.
  5. Each of them is counting on us to do our part. Each of us has a responsibility to protect our communities against measles, flu, etc.

Such display of social and political consensus won’t reach everyone. States should revisit some relatively lax exemption policies in light of disease outbreaks. I’m sure other policy changes would be useful, too.

Still, a bi-partisan campaign of goodwill can help, too. It’s not just the message. The messengers matter, too.  Some issues are larger than partisan politics. This is one.

Harold Pollack is the Helen Ross professor at the School of Social Service Administration and co-director of the Crime Lab at the University of Chicago.