On June 5, the number of measles cases in the US exceeded 1,000 this year, a milestone the country had last reached in 1992. In most circles, there is little doubt about the source of this resurgence: it is the anti-Vaxxer cases. Error. "Health officials attribute this year's outbreak to US parents who refuse to vaccinate their children," Reuters recently said in an update on the crisis.
So much goes without saying: Measles are most likely to spread in under-populated populations. If the disease spreads again, there must also be a major outbreak of vaccine refusal. However, the numbers tell a different story. As I noted here in Slate, measles vaccination rates in the US are not really decreasing. In fact, with 91 or 92 percent of the population, they are very stable over many years. While it is possible that the local trouble spots of rejection have become somewhat larger over time or that more of these communities are emerging, the evidence for this idea is rather modest.
Here's a simpler, more convincing explanation for the sudden increase in measles: Much bigger outbreaks have spread to our shores. More than 66,000 cases have been recorded in Europe since the beginning of the year and there have also been alarming outbreaks in parts of Africa and Asia. These crises have triggered those we see here. In May, the United States Centers for Disease Control and Control confirmed that the recent measles outbreaks affecting Orthodox Jewish communities in New York and the Russian-speaking communities of Clark County, Washington, began with diseased travelers Israel and Eastern Europe returned.
Are vaccination rates really declining? Again, the actual data complicates this narrative.
In other words, you do not have to report a rapid craze in the US to explain the growing public health disaster. It is certainly true that there are still a lot of vaccine denials in this country, as it has been for many years. If these bags now have a greater number of measles cases, it can be due to threatening trends in distant areas.
However, this global statement throws the can only a little further into the street. Measles cases spread here because they spread overseas. But why is measles spreading overseas?
Again, the simple and most common explanation is that anti-Vaxxer propaganda is on the rise not only here but everywhere, and worldwide immunization rates are falling. In fact, the World Health Organization got some news this year, adding the list of the top 10 global health threats for 2019 to "vaccine restraint" expanded international health experts in Geneva at a recent meeting. The latest issue of the British Medical Journal warns: "If the vaccination rates continue their downward trend, the measles could become endemic again."
Are the vaccination rates really declining? Again, the actual data complicates this narrative. Global measles vaccines are at or near an all-time high, as in the US. Since the beginning of this century, the proportion of people around the world who have received at least one dose of measles vaccine has increased by almost a fifth. In the meantime, using a second dose of the vaccine (which makes it more effective) has more than quadrupled worldwide. In 2000, only 15 percent of people received both shots. Now this number is up to 67 percent and continues to rise.
The salutary effects of all this work could not be more obvious. The global number of measles sufferers and the worldwide death toll from measles have fallen by about 80 percent since 2000, respectively. As recently as 1980, more than 4 million measles cases were reported each year. Despite the massive population growth since then – an increase of several billion people worldwide – the annual number of measles cases has fallen to about one fiftieth, to a few hundred thousand cases per year.
In the light of recent progress, the current global measles crisis appears somewhat paradoxical. Just look at what's going on in Europe. Two years ago, the region had its best vaccination year so far: 90 percent of Europeans received two doses of measles vaccine and 95 percent received at least one dose. Almost immediately, measles swept across the continent, infecting more than 80,000 people in 2018 alone and killing 72 people. This killing spree was at least three times as violent as anyone who had occurred in the recent past.
If more and more people get the vaccine, how is the comeback of the disease coming? Many different factors play a role. First, measles epidemics tend to get in waves. When a contagious disease infests a population, it quickly spreads among the most vulnerable, like a wildfire roaring through the dry undergrowth. As soon as the outbreak burns all this ready-to-use fuel, it begins to dwindle. At this time, the people who are ill are now immune and doubting parents may be more likely to vaccinate their children. Overall, the population is more resilient than before.
This leads to a feedback loop: as the vaccination rate increases, measles cases disappear. Then, when the disease becomes rarer, resistance disappears in those who can not or will not be immunized. The next outbreak will, in some cases, lead to an increase, leading to more resistance and higher vaccination rates. Measles crises alternate with "interepidemic" periods, and the pattern does not end until the immunization program reaches approximately 95 percent of the population, the threshold for herd immunity.
Given the current inadequate level of protection, periodic measles epidemics are more or less to be expected. This is because vaccination rates have apparently risen by 85 percent in recent years. Communities of vaccine skeptics, found in many different countries, contribute to this problem – but they are not the only cause. They could not even be the main cause. In the United States, for example, the number of unvaccinated children has quadrupled since 2001, a figure that people like to cite as evidence of a growing anti-Vaxx movement. But the CDC attributes this number to health inequality, as children without insurance or those living in rural areas seem to have the greatest risk.
The same is true of some of the countries where the recent measles crisis was most devastating. Madagascar has registered more than 60,000 cases since January, but not because people reject the vaccine. It's because they can not afford it. A second dose, according to this Reuters report, costs as much as a whole family could spend in a week. The weather also plays a role: studies show that vaccination rates decrease during the rainy season, when it is more difficult for people to reach the nearest clinic. A brand new Wellcome survey of 140,000 people from around the world found that 97 percent of Madagascans believe that vaccines are "important for children" (compared to 87 percent of Americans).
Another recent hot spot has been Venezuela, with almost 6,000 cases since 2018. This outbreak, too, has far more to do with access than belief: the nation's rather abrupt political and economic collapse has denied the nation the drugs. Needless to say, there is not much evidence that Venezuelan anti-Vaxxer groups have made profits on Facebook. According to the Wellcome survey, Venezuelans are at the top of the list in terms of confidence in vaccines. 93 percent agree that "vaccines are safe" and 99 percent agree that vaccines are important for children.
However, when we talk about the global measles problem, such details tend to disappear.
There are places where the mood against vaccines actually thrives, causing infections. Often, however, one finds specific, local causes of increasing skepticism. For example, in the Philippines, some parents are responding to a dangerous and recent government error. A dengue fever vaccine issued in schools was associated with fatal risks: the children who received it were at risk of developing a so-called plasma leak syndrome. Experts believe that 10 to 20 Filipino schoolchildren died as a result, and government officials are now being prosecuted for the program.
Ukraine was the source of most cases in Europe – and also the largest outbreaks in the US. The problem there was partly due to vaccine shortages from 2009 to 2016 and the continuing skepticism of the Ukrainians over flat-rate vaccinations conducted under Soviet rule. They also had a great deal of vaccination anxiety: in 2008, a teenager from Kramatorsk died of a bacterial infection less than 24 hours after a measles and rubella shot in his school. Local news media quickly linked his death to a nasty vaccination led by Ted Turner. The Ukrainian government tightened the situation by issuing its vaccination program while investigating the teenager's death, and even went to the arrest of his highest health official. The country's confidence in the MMR vaccine has not recovered since then.
However, when we talk about the global measles problem, such details disappear. Instead, we talk ad nauseam about a burgeoning anti-vaccine movement here in the US, across Europe and around the world. Nowadays it is often said that "the world is taking a step back with a dwindling belief in vaccinations" and that anti-Vaxxers "have convinced a growing number of parents to avoid the shots". Or that movement
has metastasized in social media or spread through the politics of populism or otherwise transformed into its own form of viral epidemic. A report on the anti-Vaxxer movement in Jezebel, which was released on Thursday, goes so far as to suggest that this "growing" community is "redesigning the world." Term numbers do not support the idea.
Formal efforts to analyze and address the issue of vaccine denial are still fairly new. The World Health Community began to focus on this issue following the boycott of the polio vaccine (and associated outbreak) in Nigeria in the early 2000s. The Vaccine Confidence Project at the London School of Hygiene and Tropical Medicine was founded a decade ago. Several years later, international health authorities called for substantial studies on this topic: in March 2012, the WHO Vaccination Advisory Group established a working group on vaccine retention; A year later, the US Department of Health commissioned its National Vaccine Advisory Committee to set up something similar. Each of these procedures aimed to further investigate the hesitation of the vaccine and to develop standard methods for measuring it over time.
These efforts have paid off with more and better information, but the data is still limited. In October, the vaccination trust project published the results of a comprehensive survey on the state of EU vaccination trust. The report compared the latest figures from 2018 with those from a 2015 survey. Vaccine safety ratings increased statistically significantly in eight of the 20 countries studied and remained stable in eight other countries. Meanwhile, safety ratings dropped in only four countries between 2015 and 2018: Finland, Sweden, Poland and the Czech Republic. The countrywide confidence trends were on average larger than the national declines. The largest increase in confidence in France, for example, was 16 percentage points. In Poland, the largest decrease was 7 percentage points.
The report contained some disturbing signs. First, young people in Europe are far more skeptical about vaccines than people over 65. If these millennials overseas do not change their minds as they get older, this is not a good sign of public health. However, if we focus only on the measured trends in vaccine retention in this short period (from 2015 to 2018), the news looks pretty good. If anything, the skepticism about vaccines (not to mention the mood against Vaxxer) may decrease overall.
However, you will not find this message on the news. The New York Times described the same research findings in a recent overseas measles crisis story: "According to a European Union report, the anti-vaccine movement has grown across Europe, especially in Poland." Reuters summed up the results in this heading: "Low vaccine confidence in Europe, increases the risk of disease outbreak."
The anti-Vaxxer narrative persists despite these numbers; In fact, they are even cited .
A week's BBC headline mistrust migraine was referred to as a "global crisis" when the results of this recent Wellcome survey were reported. True, Wellcome found that only 79 percent of respondents were willing to agree with the statement "vaccines are safe". On the other hand, the same study revealed that the proportion of those who objectively rejected actively agreed with the same statement was only 7 percent. (The rest did not have an opinion or refused to answer.) In terms of actual behavior, 92 percent of respondents said their children had received at least one vaccine. These global averages are in very good agreement with the results from the US. According to Wellcome, only 72 percent of Americans believe that vaccines are safe, 11 percent disagree, and 93 percent say their children have been vaccinated.
The anti-Vaxxer narrative persists despite these numbers; in fact, it even quotes it. This is because history has been determined by facts rather than by reflex, and the instinct to assume that a sudden and resurgent spread of measles must be the result of something as sudden and resurgent. Perhaps a growing disregard for mainstream expertise or a viral spread of social media fringe ideas or a major victim of the power of fake news. That makes so much sense in principle – it's so satisfying and outrageous – that statistics do not matter.
And so we have news that claims on the one hand that vaccination rates have declined in measles, and on the other hand, of exactly this sentence refer to data that show exactly the opposite. Or stories like New York's "Measles for One Percent" magazine, which relies on a shameless knack and gives the impression that the disease is a scourge of Luddite liberals whose vaccine suspicions have exploded in the course of a single generation.
It all feels very true and clear, but becomes a distraction. If we want to prevent the next round of measles epidemics, we need to look at all reasons why vaccination rates have fallen below 95 percent worldwide. Our obsession with the anti-Vaxxer does not help.