Bad information spreads like disease

State legislators last week were briefed by state health officials on vaccination issues, but say they plan no action to deal with a decline in the number of parents getting their children inoculated against various diseases. Assembly Health and Human Services Committee chair James Oscarson said the session with health officials was held mainly to let the public know that legislators are “paying attention.”

One measure, Senate Bill 117, has been introduced that would expand vaccination requirements to include inoculations for human papillomavirus and meningitis.

From Vermont to California, state legislators are considering measures to deal with the failure of a minority of parents to have their children vaccinated. Repeal of religious and personal belief exemptions are being proposed in Maine and California legislatures, while those in Montana and New York are considering making those exemptions more permissive. A surprise was that Mississippi has the best record of vaccinations—99.7 percent in both public and private schools. Only 140 students are not inoculated. The state has a very strict law that allows few exemptions—though local legislators are now trying to water that law down.

By contrast, Nevada has a 90.4 percent vaccination rate, according to the legislative briefing last week.

In 2010, 9,120 cases of pertussis—whooping cough—were reported in California, the highest number in 63 years. Initially this outbreak was attributed to factors like “waning immunity of acellular pertussis vaccines and other explanations including large birth cohorts of susceptible infants, increased detection of cases, and the possibility of genetic changes in circulating strain,” but a 2013 study in the journal of the American Academy of Pediatrics later found that “communities with large numbers of intentionally unvaccinated or undervaccinated persons can lead to pertussis outbreaks. In the presence of limited vaccine effectiveness and waning immunity, sustained community-level transmission can occur, putting those who are most susceptible to communicable diseases, such as young infants, at increased risk.”

Whooping cough, which can cause death, had declined to 20 or 30 cases in the nation each year. In Nevada alone in 2013, there were 22 cases.

The same study of the California outbreak, using census tracts, found that a failure of parents to vaccinate children happens most often in upscale households.

“In California, both NME [non-medical exemptions from vaccination requirements] and pertussis clusters were associated with factors characteristic of high socioeconomic status such as lower population density; lower average family size; lower percentage of racial or ethnic minorities; higher percentage of high school, college, or graduate school graduates; higher median household income; and lower percentage of families in poverty.”

While there is considerable folklore about the “dangers” of vaccination, there is no scientific basis for it.

Why do people buy into dumb stuff? One reason appears to be that the virtue of listening to all points of view seems to be passing away right before our eyes. In some cases, that means people are never exposed to accurate information—because they shield themselves from it. Nevada sociologist James Richardson said self-reinforcing “enclaves,” whether cultural, political or religious, are developing in society. They create their own stores of information.

“They get caught up in some cultural subgroup and they can kind of self-actuate there,” said Richardson. “You get caught up in the group and you only talk to them, and they only talk to you, and they reinforce each other’s beliefs. You get in this cul-de-sac or enclave and build up these walls and it only gets broken down if something dramatic happens, like this [vaccination crisis].”

Parents who do vaccinate but remain silent—though they represent the majority—have a role in the spread of misinformation. In an interview last week with the Reno Gazette-Journal, Immunize Nevada director Heidi Parker said, “The small amount that don’t believe in that [vaccination] are very vocal, while most parents who are vaccinating don’t speak up. It’s important for those parents to speak up and show their support for vaccinating. We need those positive voices.”

“If you’re satisfied, you don’t speak up,” Richardson said. “They’ve got other things to worry about until somebody really hits them between the eyes with a two by four, and they find their kids’ playmates are unvaccinated. … Then they become alarmed that their kids are having to interact with unvaccinated children.”

Michael Shermer, author of Why People Believe Weird Things, has written in Scientific American that people responding to anecdotes instead of evidence can cause people to miss health risks—“[W]e have evolved brains that pay attention to anecdotes because false positives (believing there is a connection between A and B when there is not) are usually harmless, whereas false negatives (believing there is no connection between A and B when there is) may take you out of the gene pool. … So it is that any medical huckster promising that A will cure B has only to advertise a handful of successful anecdotes in the form of testimonials.” Cue convicted con artist Kevin Trudeau, whose infomercials have played plenty of times on Reno television stations.

People can also be misled by people who deliberately spread bad information. While it may seem unusual or unlikely, Nevada has had plenty of experience with it. Atomic Energy Commission scientists in the 1950s and ’60s trivialized fallout dangers from atomic testing when they knew otherwise. Former U.S. House member Jim Gibbons once put his name on a report that cherry-picked the science in order to describe mercury as more or less harmless (“Mercury rising,” RN&R, Jan. 19, 2006). When she was a member of the Nevada Legislature, Sharron Angle cherry-picked scientific studies on whether there is a link between abortion and breast cancer. She cited the few studies that supported the notion and ignored the far more numerous studies that rejected the claim (“Dr. Angle’s prescription,” RN&R, July 24, 2010).

In the case of vaccinations, a 1998 paper in the British medical journal Lancet suggested a link between the measles, mumps and rubella vaccine and autism and bowel disease. The article gave birth to the anti-vaccination movement, but it was deeply flawed and most of its authors later repudiated it, as did Lancet, but lead author Andrew Wakefield—who had an undisclosed financial stake in the paper’s findings—continued promoting its conclusions and was eventually expelled from the British medical register.

Another reason for acceptance of anti-vaccine folklore is that parents who were born in the 1960s or later have not seen the dramatic impact of vaccines on diseases that were ravaging the population. Those born in the late 1940s, for instance, have vivid memories of polio stricken children in leg braces or iron lungs in the 1950s, something that they watched slowly disappear under the impact of the Salk and Sabin polio vaccines. It was a powerful lesson. Later generations did not have those experiences.

“They grew up in an era when there were no deadly diseases—because they’d been vaccinated,” Richardson said.