A Danish study has found a higher rate of autism among unvaccinated kids than those who had been inoculated for measles, mumps and rubella.
“Parents should not skip the vaccine out of fear for autism," said lead study author Dr. Anders Hviid of the Statens Serum Institut in Copenhagen to Reuters via email. “The dangers of not vaccinating includes a resurgence in measles which we are seeing signs of today in the form of outbreaks.”
Such an outbreak has been reported in Washington State, where nearly half of the nation’s cases logged through last Thursday have occurred. As of Feb. 28, 206 cases of measles had been confirmed in 11 states this year through last Thursday, according to the U.S. Centers for Disease Control (CDC). Of those, 68 are in Washington State.
Besides Washington, measles outbreaks – defined as three or more cases at a time – are California, Colorado, Connecticut, Georgia, Illinois, Kentucky, New Jersey, New York, Oregon and Texas. Some of the Oregon cases are related to the Washington State ones.
Much of the resistance to vaccination stems from a faulty study published in 1998 that claimed a direct connection between autism and vaccines. Though numerous studies have debunked that one, which has since been retracted, mistrust persists.
For the new study, researchers analyzed the data of 657,461 children born in Denmark between 1999 and Dec. 31, 2010, following up with them starting at one year old and continuing through Aug. 31, 2013, said the study, published in the Annals of Internal Medicine. Of those, 6,517 were diagnosed with autism at some point during that time period.
Nearly all – 95% – of the children studied had been vaccinated, Reuters said. The study found that children with autistic siblings were seven times more likely to be diagnosed with autism than those without a family history, with boys four times more likely to be diagnosed with the condition than girls.
“The risk for autism was no different in children who got the MMR vaccine than in children who did not,” the Annals said in a summary geared toward patients. “This remained true even among children who had risk factors for autism, such as a sibling with autism or an older father.”
Most notably, Reuters reported, “children who had no childhood vaccinations were 17 percent more likely to be diagnosed with autism than kids who did get recommended vaccinations.”
The study wasn’t seeking to prove or disprove a connection between autism and vaccines, Reuters noted, so the correlation did not point to cause and effect. Nevertheless it did indicate that vaccines and autism are not connected.
“The study strongly supports that MMR vaccination does not increase the risk for autism, does not trigger autism in susceptible children, and is not associated with clustering of autism cases after vaccination,” the researchers said in the abstract. “It adds to previous studies through significant additional statistical power and by addressing hypotheses of susceptible subgroups and clustering of cases.”