Science

Stop Talking About Measles

News reporting on the measles outbreak has a spotty record.

A child passes a sign encouraging travelers to get vaccinated against the measles.
Photo illustration by Slate. Photo by SeventyFour/iStock/Getty Images Plus and the Minnesota Department of Health.

Officials in Clark County, Washington, have now confirmed 53 cases of measles, almost entirely among the region’s unvaccinated children. Gov. Jay Inslee has declared a state of emergency, while the local public health director last week compared the virus to a lit match, and his community—where just 81 percent of children have received their first measles-mumps-rubella shot by the age of 5—to “a can of gasoline.”

Over the past few weeks, news of this outbreak has been picked up by the media outside the Pacific Northwest and characterized as a matter of grave, national importance. Stories on the “measles crisis” now suggest that it’s a sign of how the anti-vaccine movement has “metastasized” into something “so much larger and so much bigger” than it’s ever been before; that fake news about vaccines has grown more potent and persuasive on social media; and that, as a result of all this meme-contagion, an infectious disease that was once declared “completely eliminated” in the U.S. is in the midst of a deadly, disheartening comeback that’s “spreading fast.”

These claims are all misleading. The anti-vaxxer movement isn’t really on the rise all across America, and measles hasn’t really re-emerged from clinical oblivion or become a fatal threat to everyone’s well-being. The outbreak in Clark County may be disturbing, but it’s a local story: Low vaccination rates in the area, enabled by residents’ adherence to fringe beliefs and suspect statewide policies, have made this outbreak possible. But attempts to link it to a dawning crisis in America are, at best, a waste of readers’ time and trust. At worst, they might provide a boost to the anti-vaxxer movement, by exaggerating its extent and influence; or else they could distract us from other, more important obstacles to vaccination, such as health care inequality.

Here’s the most important fact that’s lost in these panicky appraisals: Vaccination rates for measles, nationwide, aren’t going down. They’ve been very stable for a while now. In 2017, the most recent year for which data are available, 91.5 percent of the nation’s children below the age of 3 had received their first dose of the MMR vaccine. Five years ago, in 2014, that figure was also 91.5 percent. Go back to 2010, and you’ll find it was 91.5 percent. What about 2005? Again, 91.5 percent.

In spite of this long-term nontrend, a canonical media narrative—and one that’s been repeated many times in recent coverage of Clark County—describes a swelling, anti-vaxxer menace to America. The story typically begins with the rise of Andrew Wakefield. In 1998, the now-disgraced gastroenterologist published an article in the Lancet asserting a causal link between the MMR vaccine and autism. While that paper would be disavowed by most of its authors in 2004, then retracted in 2010, its arguments gained a foothold in the public mind via “balanced” media coverage that pitted medical experts against concerned parents. This perspective was aided by extensive celebrity activism from figures such as Jenny McCarthy and Robert F. Kennedy Jr. According to the standard telling, the Wakefield strain of science denialism still infects the brains of ill-informed parents in Washington and Oregon today, putting the rest of us at risk.

The numbers simply don’t support this narrative, at least on the national scale. In the years leading up to Wakefield’s Lancet paper, the proportion of American 3-year-olds who had received a measles shot wavered between 91 and 92 percent—just as it has, for the most part, for the past quarter-century. For a study out last year in Health Economics, the University of Cincinnati’s Lenisa Chang analyzed the fluctuations in these rates from 1995 to 2006, to see if she could find traces of a Wakefield effect. After controlling for various other factors that might also have affected national vaccination rates—e.g., the expansion of health insurance for impoverished children—Chang found there was a significant but very short-lived drop in MMR immunizations following news coverage of the Wakefield paper. The effect was strongest in 2000, when rates were down by about 1.5 percentage points overall, but a few years later, by 2003, they had returned to their normal, pre-Wakefield levels.

If national vaccination rates have been resilient in the face of the anti-vaxxer plague, then what’s the problem? The tiny, anti-vaccine movement is not randomly dispersed throughout the country but rather concentrated in regional “hot spots” of skepticism. Overall, 91 or 92 percent of children may get their first MMR shot by age 3, but among specific, local communities—Somalis in Minnesota, Orthodox Jews in New York, hippies in Washington and Oregon—rates may sink into the epidemiological danger zone. (Experts peg the threshold for herd immunity at a vaccination rate of 93 to 95 percent. The deeper the plunge below that threshold, the more dramatic the consequences.)

The national peril, then, is said to derive from the growth of these hot spots in size and number. This trend is itself enabled by permissive immunization laws in certain areas. Every state allows parents to opt out of (or postpone) vaccinating their school-age children for legitimate medical reasons, such as the child’s having a weakened immune system. Almost all states make allowances for families’ religious beliefs, too. But in 17 states (including Washington), parents may also claim an exemption from the rules based only on their personal beliefs.

Any correlation between such lax rules and low immunization rates is not particularly clear at the state level. Among the bottom 10 states for MMR vaccine coverage, four allow philosophical exemptions; while among the top 10, three allow them. We do know that the specific children who receive exemptions are (unsurprisingly) at much higher risk for measles or other preventable diseases. A study published last summer in PLOS Medicine argued that the “hot spot” problem is getting worse, because people who have access to those exemptions are using them more often. “This is a wake-up call,” said co-author Peter Hotez to CNN when the paper came out.

Is the use of nonmedical exemptions spiraling out of control? According to the PLOS paper’s headline finding, the number of children excused from their immunization requirements for religious or philosophical reasons from 2009 to 2017 increased in 11 of the 17 states that permit the latter. There was no sign of increase among the other six states in this category.

In the meantime, a similar study published a few months earlier found that while the use of such nonmedical exemptions had indeed gone up from 2011 to 2013, it later leveled off—a promising sign described by the authors as “an important shift in trend.” The same research group, led by Emory University’s Saad Omer and Robert Bednarczyk, later found that the median proportion of children who receive nonmedical vaccine exemptions has inched slowly upward, overall, in recent years. It’s also worth remembering that these religious or philosophical exemptions are only taken by a small proportion of the population—the median rate across all states was 1.8 percent during the 2016–17 school year, with a range in values running from a low of 0.5 percent in D.C. to 6.5 percent in Oregon.

There’s a bit of disagreement here, but taken all together, the data tell us that the anti-vaxxer movement is not, in fact, going through a stage of rapid growth and that local hot spots of vaccine refusal haven’t metastasized and spread throughout the country. Nor should we worry all that much over anti-vaccine activists who pack into public hearings and try to push their local legislatures toward ever more permissive immunization regimes: According to Omer and Bednarczyk, just 11 state laws regarding vaccination were enacted in the U.S. between 2014 and 2018—and all of them strengthened existing requirements. (A similar analysis, published in December, found that 13 such pieces of legislation have been passed since 2011, of which 12 were pro-vaccine.)

What about the tragic fact, so often cited in the news, that measles—a once-vanquished disease—is breaking out again across the country? That, too, is a gross exaggeration. When news stories say that the Centers for Disease Control and Prevention declared measles eliminated from the U.S. in 2000, they tend to leave out some important context. During the most recent, major wave of measles infection in the U.S., between 1989 and 1991, close to 56,000 people fell ill and more than 100 people died. Outbreaks were not at all uncommon around this time: Several thousand cases would be reported every year, along with several dozen outbreaks among school-age children. But the 1989–91 epidemic was large enough and deadly enough to cast light on two pressing problems: First, that a single vaccine dose was not sufficient to protect children, and second, that black and Latino children, especially those living in urban areas, were less likely to be vaccinated, and thus more vulnerable to the disease.

Efforts were made to address both issues in the years that followed. A second measles shot was recommended for all children, while the federal government ramped up efforts to provide free vaccination to high-risk groups. The plan worked. By 1994, vaccine coverage for measles was closing in on 90 percent. The number of cases reported every year soon dropped from the thousands into the hundreds, and then into the tens. It was in response to this decline that experts from the CDC announced that measles had been “eliminated” from the U.S.

This was never meant to suggest that measles had been eradicated, though, or wiped out, or otherwise routed from our shores; rather that the virus was no longer circulating, all the time, among the U.S. population. Further outbreaks would always be possible—indeed, they’d be virtually assured—but only when someone brought a case of measles over from a foreign country. In fact, even as the CDC made this declaration in 2000, its experts worried that the term eliminated might be misconstrued, leading to a “false sense of security” that could itself depress vaccination rates.

At any rate, we can be a little more precise about what’s happening right now. It’s true that measles cases have been on the rise in the U.S.: We’ve hit triple-digit cases seven times in the past decade, while that happened only twice in the decade just before. And we may yet see a “national measles resurgence” at some point in the future. But this doesn’t mean that the disease has been un-eliminated due to waning vaccination rates or any other cause. Rather, it seems that we’ve been seeing more imported outbreaks. This year’s have been linked to a massive outbreak in Ukraine. The recent epidemic among Orthodox Jews in New York, for example, was traced to Eastern Europe via Israel. The strain in Clark County may be the same as well.

So, yes, measles was eliminated from the U.S. in the year 2000—and for now it’s still eliminated. Andrew Wakefield’s rise (and fall) hasn’t changed those basic facts, nor have any anti-vaxxer groups on social media.

It’s also worth considering that, even today, the incidence of measles—and its total impact on American public health—remains minuscule. Before we had a vaccine, when hundreds of thousands of people contracted the disease per year, around 1 patient died for every 1,000 sufferers. (For comparison, influenza kills 1.3 to 1.5 per 1,000 cases in the U.S.) Since 2000, there have been a total of 11 reported deaths from measles. While those 11 deaths may have been preventable, and heartbreaking and outrageous, they’re also extreme outliers. The number of Americans who die from measles every year, in this era of resurgence, matches up to the annual number of Americans who get killed by scorpions.

I’ll bet there’s anti-vaxxer propaganda that deploys such numbers, too, in claiming that measles isn’t really all that bad of a disease, or that the benefits of MMR don’t justify the risks to individuals or populations. This is wicked sophistry, of course. Widespread vaccination against measles has saved countless lives since the 1960s and continues to do so today. Obviously, emphatically: Everyone should vaccinate their damn kids—for their family’s health, for mine, and for everyone else’s, too.

But the mere fact that anti-vaxxer beliefs are treacherous and wrong doesn’t make them worthy of attention on the national scale. Vaccine refuseniks are still well outside the mainstream. They haven’t done that much to budge the average uptake rate of MMR across the country. The measles virus isn’t back in steady circulation. Deaths from measles remain very, very rare. So, what’s the point of all this consternation?

Maybe it’s strategic: By staying on high alert, we help to keep the anti-vaccine movement at the fringes of society. Measles outbreaks may be small today, but they could explode at any time, and it’s better that we panic now, even if it’s much too soon, than see what happens if we wait.

Except it’s not so clear that hypervigilance does any good. If the problem of measles outbreaks is localized to hot spots of vaccine refusal, then the solution to that problem will be just as localized. It’s the parents in Washington state, not the members of the Washington Post editorial board, who must take aggressive action. In Clark County, for example, they seem to be doing just that: Orders for the measles vaccine were up 500 percent in January, and the state is now considering a ban on philosophical exemptions.

The same pattern of response has turned up in other anti-vaxxer hot spots, too. First a measles outbreak hits a community with low vaccination rates, then laws are passed and parents change their behavior. So it was for the Disneyland outbreak in early 2015, in which more than 100 people contracted the disease from someone who had been abroad. California’s vaccination rates rose dramatically that year, then climbed even further after the state banned all personal-belief exemptions in 2016. The recent outbreak among Somali Americans in Minnesota produced a similar response, with government programs boosting vaccination rates in the community by more than one-third within a year.

These reversals don’t happen on their own. They require hard and focused work by affected families and health officials, fueled by a shared, personal sense of fear and animus. How much more is there to gain by spreading those emotions to other places, where vaccination rates are already very high? It would be nice to know that all this moral indignation served some greater purpose, but that may not be the case. I suspect the climate of opprobrium isn’t really prophylactic; rather, it’s just another way to slake an endless thirst for outrage. Anti-vaxxers are all so dumb and wrong and misinformed and selfish! Fake news has ruined everything! No one trusts their doctors anymore! Gah, it feels good.

Maybe we love to hate the anti-vaxxers because they offer us distraction. Instead of mulling over fundamental flaws in U.S. health care, we rail against the wealthy nincompoops who send their kids to Waldorf schools. That’s all a bit beside the point. Last fall, national outlets reported that, according to the CDC, the percentage of babies and toddlers who had not received any vaccines at all quadrupled since 2001. The government’s report was clear about the source of this alarming stat: Vaccine coverage remained “stable and high” among U.S. children on the whole, it said, but there were signs of special vulnerability among those in rural areas and without private health insurance. If vaccination rates were dropping, it was to some extent a function of these economic, demographic factors, not metastasizing fringe beliefs.

In the meantime, 2016 stats reveal a 2.2-point gap between rates of MMR vaccination for white and black toddlers. Compare that with the 1.5-point dip at the very peak of Andrew Wakefield’s (short-lived) anti-vaxxer influence 20 years ago. If there’s a national story here, it should be this: The racial and social inequities in vaccination coverage did not end with the measles epidemic of 1989 to 1991. In the meantime, let’s be wary of the claim that we’ve been taken by extremists to the brink of a catastrophe. For now, the outbreak of disease in Clark County isn’t likely to spread that far beyond the troubled community in which it started. Misleading viral outrage, on the other hand, appears to have no end to its transmission.