From autism risks to mercury poisoning, here are 10 lies anti-vaxxers are spreading about the measles vaccine

1. Before the introduction of measles vaccines in the early 1960s, just about every kid got the illness. Some anti-vaxxers wrongly assert that we'd all be healthier today if we continued to get measles. They've even suggested "measles parties." REUTERS/Brian Snyder Getting the measles used to be a rite of passage for children - between 95% and 98% of children got it by their 18th birthday. Before the vaccine was introduced, some parents tried to get their kids sick with the measles when they were young, since a case of the measles, like chicken pox or shingles, can be more severe when you're an adult.

But even a run-of-the-mill measles case can be torturous. Melnick remembered having it as a young child. REUTERS/Ali Owidha "You're miserable with measles. We're talking about high fever. We're talking about being sick for at least a week," he said. "I remember being in bed for a long period of time with the blinds closed, because when you get those red eyes you get what's called photophobia," sensitivity to light. Kids who are younger than 5 and adults over 20 are more likely to develop measles complications; some of the most common include ear infections and diarrhea. "Even without complications, it is not very pleasant," Melnick said. "I wouldn't wish it on my worst enemy." Studies have found that babies who get the measles very young have lower mean weights than other infants, suggesting that contracting the virus may have a lasting effect on growth.

2. Unfortunately, a discredited doctor named Andrew Wakefield has led many people to mistakenly believe that there's a link between autism and the measles vaccine. REUTERS/Luke MacGregor Wakefield's research on autism and vaccines has been discredited. His main paper on the subject has been retracted, and other studies since have found no link between autism and vaccines. One investigation suggested that part of Wakefield's motivation was money. Wakefield once "proposed starting a company that could reap huge returns from molecular viral diagnostic tests," the journalist Brian Deer found in an investigation published in the BMJ in 2011. The scheme "predicted a turnover from Britain and America of up to £72.5m a year," he said.

Measles killed more than 400 kids every year in the US before a vaccine was invented. By contrast, the most recent measles death in the US was one adult case in 2015. AP Photo The Centers for Disease Control and Prevention estimated that from 1994 to 2013, vaccines prevented more than 70,000 measles cases in the US, including over 8,800 hospitalizations and more than 57 deaths. The last known measles death in the US was a Washington woman with a compromised immune system who died in 2015 from pneumonia that resulted from measles. She's an example of one of the few people who shouldn't get the vaccine, and of someone who's at risk when there's no herd immunity.

3. Anti-vaxxers sometimes suggest that because the measles is a live virus, the vaccine will make a person who gets the shot contagious. This is not true. UNICEF/Handout via REUTERS The measles vaccine is a weakened version of the live virus, and you're not contagious after getting the shot. You may have some mild reactive symptoms like a sore arm, a rash at the injection site, or a slight fever, but this is your body building up its immunity. Kids who get infected with the measles, on the other hand, can shed the virus for several weeks after their infection is over, thereby transmitting the illness to others. Infected people also may not know that they're sick right away, since the initial symptoms are similar to the common cold (runny nose, cough, fever, and pink eyes). "You can have those for several days before the rash starts, and you're contagious for that period," Melnick said. The measles can also hang out in the air for two hours after a contagious person has left a room.

4. Vaccine opponents often argue that drug companies sell vaccines to make money. Actually, they'd make more money if they didn't offer vaccines. REUTERS/Nacho Doce Vaccines, which cost about $12 a pop, provide cheap protection against common illnesses. Unlike the drugs we take when something goes wrong, a vaccine dose (or two) usually lasts a lifetime. That's not a great moneymaking strategy for Big Pharma. "By itself, Lipitor, an anticholesterol drug, brings in more revenue - about $12 billion this year - than the entire vaccine market," The Wall Street Journal reported in 2005. Every dollar spent on the vaccine for measles, mumps, and rubella saves an estimated $14 to $26 in healthcare costs, including both the direct costs of caring for sick kids and the larger socioeconomic effects. As Bill Gates likes to point out, vaccines provide a better return on investment than the stock market.

5. Some who rail against vaccines worry that a measles vaccine could cause kids to get more seizures. Again, not true: Febrile seizures are often triggered by fevers, and more measles cases means more fevers overall. Jim Goodson, M.P.H. / CDC "Any child with a fever can get what's called a febrile seizure," Melnick said. These baby spasms, he added, are horrible to watch but typically benign. "The disease causes a lot more fever than the vaccine ever does or ever will," he said.

6. The same is true of encephalitis: It's far more common to experience brain swelling because of the measles than the vaccine. Centers for Disease Control and Prevention One in every 1,000 people who get the measles develops the brain-swelling condition. Other severe (and rare) complications from measles can affect every organ system in the body. Death from measles is rare, but problems can include pneumonia, croup, seizures, appendicitis, hepatitis, corneal scarring, blindness, and renal failure.

7. Melnick also said some anti-vaxxers express concerns that the measles vaccine contains mercury. It does not. AP Photo/Gillian Flaccus Some mercury is used as a preservative in flu vaccines, which may be the source of the confusion. But even so, it's not a dangerous ingredient, and it isn't in single-use vials. "The mercury in there is not the kind that causes a neurologic problem," Melnick said. "It's not in the measles vaccine anyway."

8. Some parents who don't vaccinate their kids think measles wouldn't be a problem if people just got enough vitamin A. This conflates the issue of malnutrition with vaccination. Thomson Reuters Vitamin A deficiency makes it tougher for the body to fight all kinds of infections, including the measles. But vitamin A does not prevent measles. Generally speaking, when your health is better and you have access to better food and nutrition, you'll handle the measles better and have fewer complications. Even before a vaccine was developed, the death rate from measles in the US plummeted in the first half of the 20th century, to one death per 1,000 cases from 25 per 1,000. That's because more people in the US were better fed and transitioned to less crowded living conditions. But that doesn't mean we've developed a natural immunity or that we should treat the measles as no big deal. "People become complacent because they don't realize how bad it can be," Melnick said. "And that's what scares me the most."

9. Some anti-vaxxers wrongly suggest that people have died from the measles vaccine. Ellis Island Portfolio/New York Public Library Public Domain Collection For this flawed argument, anti-vaxxers often point to a federal database called VAERS maintained by the CDC. However, the database makes clear that a report of a death after a vaccine administration doesn't necessarily mean the vaccine is what caused the death. What's more, there's a wealth of evidence from decades of vaccine administration around the world that otherwise healthy children and adults who get a measles vaccine don't die from it. It's true, however, that there have been a few cases in which someone has died after getting a vaccine. The causes include severe allergic reactions (which can be treated by a clinician if a shot is administered in a clinic) and severe immunodeficiencies.

Many parents assert that not vaccinating their children is a personal matter. But vaccinations protect others from illness too, especially kids like Rhett Krawitt (shown below) who can't get shots because their immune systems are too vulnerable. Reuters/Elijah Nouvelage "I respect people's choices about what to do with their kids, but if someone's kid gets sick and gets my kid sick, too, that's a problem," Carl Krawitt, Rhett's father, told The New York Times in 2015, amid a measles outbreak in nearby Orange County.

10. Some parents of vaccinated kids in the Pacific Northwest say they might keep their youngsters home from school until the threat is over. That's not really necessary, as the vaccine is 93% effective after the first dose and 97% after the second. Flickr via wwworks "About 3 out of 100 people who get two doses of MMR vaccine will get measles if exposed to the virus," the CDC says, adding that those few cases will be milder and that those people are less likely to spread measles to other people.