Anti-vax myths have existed for centuries, at least since the British physician Edward Jenner developed the smallpox vaccine in the 1790s. And they persist even in our so-called scientific era: after a 30% increase in measles outbreaks in the world, in 2019, the World Health Organization (WHO) has ranked the anti-vaccine movement among the worst threats to the health of humanity.
Steps have been taken to stop the anti-vax misinformation: in February 2019, Pinterest updated its search function so that the keywords related to the vaccination can no longer return results and YouTube has confirmed that she was removing advertisements from the channels promoting anti-vaccination rhetoric. Meanwhile, health experts have asked Facebook to close its many anti-vax pages, viewed millions of times.
To help us reduce noise, we examine the origin of nine of the most important anti-vaccine claims and determine if there is scientific evidence about them.
1. Vaccines cause autism.
Where does the myth come from: One of the most important claims of anti-vaxxers is that vaccines are linked to autism: an autistic child can be diagnosed as early as 12 to 18 months of age – around the same time the vaccine is measles, mumps and rubella (MMR) is administered – which leads some parents to assume a cause and effect relationship. British gastroenterologist Andrew Wakefield published a shocking study in The lancet in 1998, combining the MMR vaccine with autism and intestinal diseases.
The link between autism and vaccines is repeated often, including by celebrities such as Jenny McCarthy, who told Oprah in 2007 that vaccines had triggered autism from her son, and President Donald Trump, who claimed in 2015 that after being vaccinated, a child had a terrible fever. very sick, [and] now, it is autistic. According to a Pew poll conducted in 2015, one in ten parents believe that the MMR vaccine is not safe.
Facts: In 2004, the Sunday Time Wakefield, who allegedly intended to create a company that would benefit from the explosion of medical tests and lawsuits that would follow his report, reported financial conflicts of interest. After discovering that his research was fraudulent, Wakefield's co-authors withdrew their support and his stuy was retracted by The lancet. "The statements in the paper were totally false," said Richard Horton, editor-in-chief. The Guardian"I feel that I've been cheated."
In 2009, a British administrative court stated that "there is now no respectable group of opinions that supports the hypothesis that the MMR vaccine, autism and l & # 39; enterocolitis. [a devastating intestinal disease affecting premature infants] have a causal link. "Wakefield's medical license was revoked a year later.
2. Vaccines do not really work.
Where does the myth come from: Some skeptics about vaccines say there is no guarantee that vaccination will prevent disease. Vaccinated people still contract the virus, sometimes more than unvaccinated people. Facts: No medical treatment is 100% effective, and so are the vaccines: the flu vaccine is less effective, it will probably only immunize you against the flu about half the time. But two doses of measles vaccine have an effectiveness rate of 99%.
Given that the number of people vaccinated in the United States is significantly higher than that of unvaccinated people, the small minority of vaccinated Americans who contract a disease during an epidemic may exceed the total number of unvaccinated persons: Imagine 1,000 fully vaccinated people and five unvaccinated people are all exposed to measles. Even if only 1% of vaccinated people fall ill, this is more than all unvaccinated people combined. And even though all unimmunized people have caught measles, the majority of the victims have been vaccinated. This statistic, used in isolation, has been used to "prove" that vaccines are useless. Of course, this does not take into account the 988 vaccinated people who were exposed to measles but did not catch it.
3. Vaccines contain toxins.
Where does the myth come from: In addition to a version of the virus he is fighting against, a vaccine usually contains preservatives and other chemicals that keep it stable. Thiomersal, a preservative traditionally used in tetanus and diphtheria vaccines, contains traces of mercury. And adjuvants, which help the immune system respond to a vaccine, often contain aluminum. This has led vaccine skeptics to claim that the vaccines are filled with toxic substances.
"The California government says yes to the mandatory poisoning of mercury and aluminum to more children [sic] vaccines, "actor Jim Carrey tweeted in 2015." This fascist enterprise must be stopped. "
His tweet, still in the news, has received thousands of "likes".
Facts: The level of mercury or aluminum used in a vaccine is too low to constitute a danger beyond a mild allergic reaction, such as redness at the site of the injection. In 2012, the WHO's Global Advisory Committee on Vaccine Safety (GACVS) found that mercury levels in babies' blood had returned to baseline levels one month after vaccination. Even with vaccines based on the GACVS determination, mercury levels have never reached toxic levels. He revealed that studies linking thiomersal to neurodevelopmental disorders were "marred by methodological flaws". Two years later, an Australian study of more than one million children also revealed no link between thiomersal content in vaccines and autism.
4. Vaccines can overload the baby's immune system.
Where does the myth come from: Some anti-vaxxers claim that vaccines result in the activation of specialized immune cells in your brain. Too many vaccines over a short period of time can excessively stimulate these cells, forcing them to release toxins that cause brain damage.
Facts: Vaccines activate only a tiny part of the baby's immune system. "Children are exposed to more antigens from a cold than from vaccines," says Flavia Bustreo, of the WHO. "Giving multiple vaccines at the same time has no negative effect on a child's immune system. This reduces the discomfort of the child and saves time and money. "
In addition, children are vaccinated at a young age because they are most vulnerable to the disease. Postponing or refusing vaccinations can have disastrous consequences.
5. Natural immunity is safer than the immunity gained through vaccination.
Where does the myth come from: Catching a disease can give people a more effective immunity than a vaccination.
In February 2019, Darla, the wife of the White House's communications officer, Bill Shine, tweeted, "I had the #Measles #Mumps #ChickenPox like all the kids I knew. Unfortunately, my children had #MMR for never having the long natural immunity that I had.
Facts: Yes, gaining immunity by surviving a disease is a more effective barrier for subsequent reinfection. But the disease is invariably more painful – and potentially more deadly – than any vaccine, which can result in mild side effects, such as mild fever or pain at the injection site. But the side effects of diseases like polio and diphtheria can include breathing problems, paralysis, heart failure and even death.
Prevention is better than cure: the probability of dying from measles is one in 500. The chances of developing a life-threatening allergic reaction to MMR are one in a million.
6. There are natural and effective homeopathic alternatives to vaccines
Where does the myth come from: In 2017, a former naturopathic doctor said L & # 39; Atlantic She met with a naturopath who suggested that elderberry syrup could replace the flu shot.
Some homeopaths offer alternatives to conventional vaccines: called "nosodes", they contain infected biological materials – usually tissue, blood or nasal secretions – which have been diluted dozens of times with distilled water or alcohol. Nosodes for human use are available for everything from smallpox to anthrax, at a dilution of 30 or 200.
Facts: There is no scientific evidence of the effectiveness of homeopathic vaccines. Extreme dilution means that there are basically no more molecules of the infected material in the substance. This is probably a good thing, but parents who avoid vaccines in favor of ineffective remedies for homeopaths leave their children exposed to deadly diseases.
7. Good nutrition and good hygiene will protect you from most viruses.
Where does the myth come from: In the 19th century, improved sanitation, nutrition and hygiene contributed greatly to the fight against endemic viruses and bacteria. Some skeptics about vaccines realized that this meant that diet and lifestyle were the only defenses we needed.
Facts: The number of polio cases in the United States peaked in the early 1950s, long after the quality of sanitation and nutrition became the norm: rich and poor children, like the disease, who did not Only disappeared in 1979, a generation after the introduction of the first polio vaccination strategy in 1955 And even the healthiest diet will not protect you from tetanus or measles.
8. Vaccines are just one way for doctors and pharmaceutical companies to make money.
Where does the myth come from: According to WHO, the vaccine market is growing rapidly, from $ 5 billion in 2000 to nearly $ 24 billion in 2013. In 2016, Pfizer's best-selling pharmaceutical product was Prevnar, a vaccine that prevents infections caused by pneumococcus bacteria. This news has fueled the popular theory that Big Pharma is developing and growing unnecessary and even harmful vaccines to generate huge profits.
Facts: Pharmaceutical companies make money with vaccines, but they are not particularly profitable, especially when compared to drugs used to treat an epidemic. Vaccines represent only about 3% of the total pharmaceutical market. The recent expansion of the vaccine market is actually due to the large population and economically emerging countries, such as China, which have introduced rigorous vaccination programs for the first time.
Among the 15 largest US pharmaceutical companies in 2017, Prevnar was the only vaccine to be on the list, in 12th place. Drugs treating chronic diseases are much more lucrative. If something is really underutilized, vaccines: A 2018 report from the Access to Medicine Foundation accuses Big Pharma of neglecting to develop an infant vaccine against cholera.
And if the medical community wanted to earn more money, it would fight against vaccines: a measles outbreak in San Diego in 2008, which started with an unvaccinated boy and led to 11 cases, cost more than 124 $ 000 to public health authorities, a study published in the journal pediatrics. In addition to the cost of treating each case, public health officials had to spend more than $ 37,000 to quarantine 48 children too young to be vaccinated.
And in 2011, the cost of fighting 16 measles outbreaks cost taxpayers between $ 2.7 and $ 5.3 million: "In addition to the impact on local and regional public health cases of measles also affect hospitals, clinics and non-health public services such as schools, universities and sometimes local police agencies applying quarantine measures ", reports the CDC . That's exactly what the public pays – measles infections often require hospitalization and patients' medical bills can reach tens of thousands of dollars.
Meanwhile, the CDC is setting a single dose of MMR vaccine at $ 21.05.
9. Vaccines are not needed
Where does the myth come from: Herd immunity – when enough groups are vaccinated so that a disease can spread easily – protects unvaccinated members of society. Skeptics about vaccines say that means they do not have to vaccinate their children.
Facts: It is thanks to intensive vaccination programs that diseases such as measles and poliomyelitis are so rare: the United States has witnessed more than 440,000 measles cases each year before the introduction of measles vaccine in 1963 In 1970, the number of new infections was reduced to one tenth. In the last decade, measles infections have decreased between 55 and 667 per year.
But herd immunity requires overwhelming majority adherence: during a measles outbreak in 2019 in the state of Washington, most of the 65 infected infants are n & # 39; 39, were not vaccinated. In fact, school records show that only 76.5% of the county's children have received all their vaccines – well below the 95% required for herd immunity.
Until now, the immunity of the flock has been able to accommodate parents who hold back their children's vaccines. But there is a turning point: to achieve collective immunity against measles, at least 90% of the population must be vaccinated. (Between 1988 and 1990, 75 people in California died from measles after an outbreak caused by unvaccinated communities.) Polio, less contagious, still required 80-85% of the population vaccinated against measles. herd immunity.