Children who receive the measles, mumps and rubella (MMR) vaccine are not at increased risk for autism, and that includes children who are sometimes considered to be in "high risk" groups for the neurodevelopmental disorder, a massive new study finds. The new study, published today (March 4) in the journal Annals of Internal Medicine, is one of the largest studies of its kind to date. In it, researchers looked at the records of more than 657,000 children born in Denmark between 1999 and 2010, including about 6,500 who had received an autism spectrum disorder (ASD) diagnosis. ASD is a neurodevelopmental condition that affects a person's ability to communicate, interact and behave appropriately with others in social situations. The study shows, as many before it have time and again, that "[caregivers] shouldn't choose to not vaccinate because of this punitive association between the MMR [vaccine] and autism," said study principal investigator Anders Hviid, a senior researcher in the Department of Epidemiology Research at Statens Serum Institut in Copenhagen. "There's really strong science that there is no association." [Beyond Vaccines: 5 Things That Might Really Cause Autism] The idea that the measles component of the MMR vaccine might be linked to autism began with a small, now-retracted 1998 study in the journal The Lancet. That research looked at 12 children with developmental delays, and eight of the kids had autism. It's since come to light that the lead researcher had several conflicts of interest: He had been paid by a law firm that wanted to sue the vaccine manufacturer, and he had a patent for a "safer" measles vaccine that he had developed before doing the 1998 study, according to a 2011 report in the journal The BMJ. Since 1998, countless studies have found no link between the MMR vaccine and autism, including a large 2002 study in The New England Journal of Medicine that Hviid carried out with his colleagues; that research looked at 537,000 children born in Denmark between 1991 and 1998. But after the publication of that study, Hviid heard from concerned parents and so-called anti-vaxxers who questioned whether "susceptible" children might be at risk for autism after receiving the MMR vaccine. "We saw an opportunity to re-examine the association in the same setting but with new children," Hviid told Live Science. "We also looked at how we could address some of the criticisms of our original study." What they studied In the new study, in addition to looking at the big picture (whether the MMR vaccine increases autism risk in all children), the researchers looked at whether the vaccine increased risk in the following groups: boys, girls, children who develop "regressive autism" when they're older and children whose siblings have autism (the condition is partly genetic, so these children already have a greater risk of developing autism than the general public does). The scientists also looked at individuals' birth years, whether other childhood vaccines were received and when, and each child's autism risk factors based on the child's disease risk score, the researchers reported in the study. In the results, none of the subgroups that received the MMR vaccine showed any increased risk for autism, the researchers found. Interestingly, the vaccine was even associated with a slightly lower risk of autism in girls and in children born from 1999 to 2001, the researchers reported. What increases autism risk? It's still unclear what biological mechanisms cause autism. But the study did find which groups were at highest risk for autism: boys, children born more recently (from 2008 to 2010), children who had no early vaccinations and, as mentioned, those who had siblings with autism. Other risk factors included having older parents, a low birthweight, a preterm birth and a mother who smoked during pregnancy. [7 Ways Pregnant Women Affect Babies] The study is a "well-conducted investigation" showing what other studies before it have: that getting the MMR vaccine does not increase a child's risk of autism, said Kristen Lyall, an assistant professor at the A.J. Drexel Autism Institute at Drexel University in Philadelphia, who was not involved in the study. This research also makes "the important contribution that even among groups with increased susceptibility to autism, MMR vaccination is not associated with autism," Lyall told Live Science in an email. In an editorial published alongside the study, Dr. Saad Omer, a professor at the Emory Vaccine Center at Emory University in Atlanta, who was not involved with the study, said that the need to disprove anti-vaccine ideas comes at a cost. While large epidemiology studies may not cost as much as other types of research, he said, they do divert time that scientists could otherwise spend finding causes and treatments for autism. "Irrespective of the absolute costs, the opportunity cost of this research should be kept in mind: For example, continuing to evaluate the MMR-autism hypothesis might come at the expense of not pursuing some of the more promising leads" related to autism's causes and treatments, Omer wrote in the editorial. Originally published on Live Science.<doc-sep>The MMR vaccine, which protects against measles, mumps, and rubella, does not increase the risk of autism, researchers in Denmark report in a new study. In the late 1990s, a British physician named Andrew Wakefield published a now-retracted study claiming to have found a connection between autism and the MMR vaccine. It was later revealed that he faked some of his data, and Wakefield can no longer practice medicine, but his report is still fueling the anti-vaccination crowd, which maintains a link exists. The Danish study, published in the Annals of Internal Medicine, specifically focused on criticisms from people who think vaccinations are dangerous. The researchers looked at children who have a sibling with autism and those with older parents, for example, to see whether some kids are more likely to be diagnosed with autism following an MMR vaccination, The Guardian reports. Overall, the study followed 657,461 children, 6,517 of whom were diagnosed with autism over the decade-long study; 95 percent of the children received the MMR vaccine. The team found that children who were given the MMR vaccine were 7 percent less likely to develop autism than kids who did not get vaccinated, and that kids who did not receive any vaccinations were 17 percent more likely to be diagnosed with autism than kids who did get them. They also determined that kids with autistic siblings were roughly seven times more likely to be diagnosed with autism than those who did not have that family connection. Dr. Anders Hviid of the Statens Serum Institut in Copenhagen, the study's lead author, made it clear that that vaccines should not be skipped due to fear of autism. "The dangers of not vaccinating includes a resurgence in measles, which we are seeing signs of today in the form of outbreaks," he told Reuters.<doc-sep>Take a quick look at these numbers; 657,461 children born between 1999 and 2010. Of those, 6,517 diagnoses of autism spectrum disorder (ASD). More than half a million years of human life in total. Zero signs of any link between the measles-mumps-rubella (MMR) vaccine and autism. It all adds up to one of the largest studies to date investigating allegations that vaccines could be responsible for the development of ASD. But big numbers aside, was it worth the bother? It's been more than 20 years since the discredited British researcher Andrew Wakefield sparked global hysteria with his claim a common inoculation was in some way responsible for impairing neurological development in young children. Studies have since failed to support the claim over, and over, and over again. By all accounts Wakefield's study should have long become a textbook example of self-correction in science. We should have moved on. Yet here we are in 2019 with another monumental epidemiological study asking whether we've missed something, whether maybe – just maybe – there's a stone left unturned. By taking into account known risk factors for autism and modelling them in connection with the MMR vaccination status of more than half a million subjects, a team of researchers from Statens Serum Institut could rule out even the smallest of chances that the vaccine triggers ASD development. Autism is a rather complicated condition. There are numerous characteristics contributing to a diagnoses, and diverse severities that make it less a single disorder and more of a spectrum of behaviours and functions. ASD might or might not be on the rise, depending on how you interpret the statistics as an indication of shifts in diagnostic trends or as a sign of something more profound. Part of the problem is we're only getting to grasp just how many factors might be at work. There are clearly a variety of genes that make some difference, many of which can be inherited. Environmental factors such as air pollution also seem to nudge developing biochemistry further towards the autism spectrum. In spite of Wakefield's work being retracted from the journal in which it was published, researchers have continued to probe the increasingly remote possibility that vaccines might still play a role in the disorder's development. It's not like there is a lingering doubt within the medical community. But as vaccination rates decline across many parts of the globe and anti-vaccination groups promote misinformation across media platforms, science supporting the relative safety of vaccines remains at a premium. "Social media continues to be a platform to propagate this and other fake news about vaccines, creating concerns among parents," says Kristine Macartney, Director of the Australian National Centre for Immunisation Research and Surveillance. But is more science really the answer? Macartney wasn't involved with the initial research, but feels in spite of its merits, future studies such as this one come at a cost. "Looking forward, continuing to evaluate the MMR-autism myth when it has already been thoroughly debunked will come at the expense of not pursuing other important research to better understand and prevent autism." Hannah Kirk from the Monash Institute of Cognitive and Clinical Neurosciences agrees. "Although it is fantastic to see another high-quality study refute the myth of an autism and MMR vaccine link, it is disappointing that substantial research efforts, time and funds have to continue to be directed toward disproving something that we already know to be incorrect; rather than investigating more accurate causes of autism," says Kirk. Not only are we desperate to know more about the neurology of the autism spectrum, there's a great deal of study left to be done on how to better communicate and change public opinion when it comes to vaccinating our families. Based on what little we do know, bigger and better studies aren't going to persuade hesitant parents into giving their precious ones a jab of MMR. "Perhaps it is time to finally lay to rest the false information that MMR causes autism and get on with the important goal of eradicating this deadly disease once and for all," says infectious diseases physician Katie Flanagan from the University of Tasmania. In 2017, an estimated 110,000 people around the world died as a result of measles outbreaks in areas that weren't adequately protected by vaccination. If there's one number we really need to pay attention to, it's that one. This research was published in the Annals of Internal Medicine.<doc-sep>
(CNN) — The measles, mumps, and rubella vaccine does not increase the risk of autism and does not trigger autism in children who are at risk, according to a new study of over 650,000 children. Researchers used a population registry to evaluate whether the MMR vaccine increased the risk of autism in children born in Denmark between 1999 and 2010. A total of 657,461 children were followed through August 2013, with the researchers documenting diagnoses of autism spectrum disorder as well as known risk factors including age of the parents, diagnosis of autism in a sibling, preterm birth and low weight at birth. Over 95% of the children received the MMR vaccine, and 6,517 were diagnosed with autism. The MMR vaccine did not increase the risk of autism in children who were not considered at risk for the disorder and did not trigger it in those who were, according to the study, published Monday in the journal Annals of Internal Medicine. “This idea that vaccines cause autism is still around and is still getting a lot of exposure in social media,” noted Anders Hviid, lead study author and senior investigator at Statens Serum Institut in Denmark. With anti-vaccine groups becoming more vocal and even celebrities and politicians spreading fear of vaccines, Hviid and his team wanted to provide solid scientific answers. The biggest contribution of the study was the inclusion of children at risk of autism, said Dr. Paul Offit, director of the Vaccine Education Center at Children’s Hospital of Philadelphia, who was not involved in the new research. He hopes the latest piece of evidence will reassure families with young children at risk of developing autism spectrum disorder that the vaccine will not increase that risk. The myth linking vaccines and autism grew out of a 1998 study by Andrew Wakefield, published in the medical journal The Lancet. Wakefield had been compensated by a law firm intending to sue manufacturers of the MMR vaccine, and in 2010, he lost his medical license. In 2011, The Lancet retracted the study after an investigation found that Wakefield altered or misrepresented information on the 12 children who were the basis for the conclusion of his study. Several subsequent studies trying to reproduce the results have found no link between vaccines and autism. “At this point, you’ve had 17 previous studies done in seven countries, three different continents, involving hundreds of thousands of children,” Offit said. “I think it’s fair to say a truth has emerged.” Yet the myth of a link between vaccines and autism continues to be used by anti-vaccine activists, who have been blamed for the ongoing measles outbreaks across the United States. At least 206 US cases of measles have been recorded in 2019, after 372 cases in 2018, according to the US Centers for Disease Control and Prevention. Around the world, measles cases increased by 48.4% between 2017 and 2018, according to UNICEF calculations from World Health Organization data. Ten countries, including Brazil, the Philippines and France, accounted for nearly three-quarters of the total increase in measles cases in 2018. Get CNN Health's weekly newsletter Sign up here to get The Results Are In with Dr. Sanjay Gupta every Tuesday from the CNN Health team. The World Health Organization has deemed vaccine hesitancy – the reluctance or refusal to vaccinate despite the availability of vaccines – as a top 10 threat to global health in 2019. “I think we are at a tipping point,” Offit said. “I think people need to realize that a choice not to get a vaccine is not a risk-free choice. It’s a choice to take a greater risk, and unfortunately right now, we are experiencing that greater risk.” CNN’s Debra Goldschmidt and Nina Avramova contributed to this report.