When, as a teenager, I first watched the groundbreaking Stanley Kubrick satire Dr. Strangelove, it scared the heck out of me. The final scene, when Dr. Strangelove's Doomsday Machine sets off worldwide nuclear (brilliantly set to the pop tune "We'll meet again" . . . some sunny day), captured the anxiety of a generation that grew up fearing that mad scientists and their complicit politicians, would end up getting us all killed.

Today, I fear that it's the mad anti-scientists, and their complicit politicians, who may end up getting us killed. Because of science-denying people who refuse to vaccinate their children and themselves, the United States is experiencing a measles outbreak that so far has infected at least 121 people, mostly children, in 17 states, including Pennsylvania and Delaware. As the Philadelphia Inquirer's editorial board observed in a February 8 editorial, Vaccinate Your Child, Pennsylvania "is particularly susceptible to" measles, mumps, and rubella (MMR), because only 87% of its kindergarten-age children are vaccinated against these diseases, among the lowest in the country. In New Jersey, 97% of kindergarteners are vaccinated.

Make no mistake about it: measles not only is highly infectious, it kills.  In the late 1950s, before the first licensure of a measles vaccine in 1961, "an average of 150,000 patients had respiratory complications and 4000 patients had encephalitis each year; the latter was associated with a high risk of neurological sequelae [harm] and death. These complications and others resulted in an estimated 48,000 persons with measles being hospitalized every year."

I have no doubt that the anti-vaxxers are sincere in wanting to protect their kids against what they believe are "dangerous" vaccinations, except that their beliefs are directly contradicted by the scientific evidence.   My Philadelphia-based employer, the American College of Physicians, is the largest physician specialty membership society in the world, representing 141,000 internal medicine physician specialists and medical student members.  On February 4, the College issued a statement declaring that

"The scientific evidence clearly supports the benefit of the MMR vaccine and the lack of any association with autism. Physicians have a duty to provide the best care for their patients, as well as to protect the public health. At the same time, the profession has a duty to advocate based on accurate scientific data. Patient/parent autonomy is not absolute when it has the potential to compromise both individual and public health. Thus, we urge all Americans to embrace the sound preventive medicine practice of both routine pediatric and adult immunizations."

The American Academy of Pediatrics, Centers for Disease Control and Prevention, and the World Health Organization have affirmed the same: the MMR vaccine is safe, doesn't cause autism, and saves lives.

It doesn't help, though, when parents' anxieties about vaccine safety are stoked by pandering politicians. Or when a small, yet influential, number of physicians spread falsehoods about the safety of vaccinations, which one prominent medical ethicist argues should be grounds for having their licenses revoked.

My fear about the impact of the anti-science movement though, isn't limited to vaccinations.  Because of people who deny the science of climate change and oppose policies to mitigate it, we are looking at a future of "extreme heat waves, rising sea-levels, changes in precipitation resulting in flooding and droughts, intense hurricanes, and degraded air quality,[which will] affect directly and indirectly the physical, social, and psychological health of humans. . . climate change can be a driver of disease migration, as well as exacerbate health effects resulting from the release of toxic air pollutants in vulnerable populations such as children, the elderly, and those with asthma or cardiovascular disease."

In a free country like the United States, everyone is entitled to their opinion.  But when your opinions put us all at risk, it is time for the rest of us to speak out, and demand public policies—and politicians who will carry them out--that are grounded in science, not mad anti-science denialism.