{"id":83292,"date":"2025-06-16T12:07:28","date_gmt":"2025-06-16T18:07:28","guid":{"rendered":"https:\/\/www.uchealth.org\/today\/?p=83292"},"modified":"2025-11-07T08:02:23","modified_gmt":"2025-11-07T15:02:23","slug":"mmr-vaccines-do-not-cause-autism","status":"publish","type":"post","link":"https:\/\/www.uchealth.org\/today\/mmr-vaccines-do-not-cause-autism\/","title":{"rendered":"The evidence is clear. MMR vaccines do not cause autism."},"content":{"rendered":"
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\"Decades
Decades of research confirm that there is no link between the MMR vaccine and autism. Science, safety data and history all support this fact. In Colorado, nearly 94% of children get their MMR vaccines, but health experts would like to increase those rates since measles cases are on the rise. Photo: Getty Images.<\/figcaption><\/figure>\n

As of mid-May, health experts at the U.S. Centers for Disease Control and Prevention had tallied more than 1,000 cases of measles in the U.S. this year, including a handful in Colorado<\/a>. Three people with measles, including two young children, have died in Texas, where the current outbreak started.<\/p>\n

Those three deaths among roughly 1,000 cases showed an unlucky affinity to the statistics compiled before the measles vaccine\u2019s approval back in 1963. Before then, nearly 4 million people a year contracted<\/a> this highly contagious virus each year in the United States alone, with 1 in 20 ending up with pneumonia, one in 1,000 having brain swelling that could cause deafness and intellectual disability, and, yes, three in 1,000 dying. About 48,000 were hospitalized each year, despite a population just over half of today\u2019s.<\/p>\n

In 1971, the U.S. Food and Drug Administration approved the first combined measles, mumps, rubella (MMR) vaccine. Its mass rollout dramatically reduced<\/a> the number of U.S. measles cases by more than 99%. By 2000, measles had been eradicated in the United States.<\/p>\n

But measles is back \u2014 despite U.S. MMR vaccination rates above 90% (schools generally require it). The issue is that the extreme transmissibility of measles (nine in 10 of those unvaccinated will contract it when exposed) means that 95% of the population must be immunized to achieve herd immunity.<\/a> Colorado\u2019s current MMR vaccination rate stands at 93.7%. Why it\u2019s not higher rests largely at the feet of<\/a> a fraudulent and discredited<\/a> 1998 British study of a dozen cherry-picked cases.<\/p>\n

Subsequent studies from around the world involving hundreds of thousands of subjects all have<\/a> come<\/a> to<\/a> the<\/a> same<\/a> conclusion<\/a>: MMR vaccines do not cause autism. In fact, a major Danish study found<\/p>\n

\u201cWe\u2019ve got a half-century of data on this. There\u2019s no connection,\u201d said Ross Kedl, who has a doctorate and is an immunologist and vaccinologist<\/a> at the University of Colorado School of Medicine<\/a> on the Anschutz Medical Campus<\/a>.<\/p>\n

Vaccine safety is serious business<\/strong><\/h2>\n

Don\u2019t take his word for it, Kedl says. The studies are out there on PubMed<\/a> and elsewhere.<\/p>\n

\u201cNobody\u2019s hiding data. Nobody\u2019s being secretive. Nobody\u2019s stashing away hidden studies,\u201d Kedl says. \u201cIf scientists have an answer, for God\u2019s sakes, we want the world to know. So we publish everything, because our reputations are based on that.\u201d<\/p>\n

In other words, if vaccines really did cause autism, scientists such as Kedl would get the word out. Researchers have kids, too, after all.<\/p>\n

What\u2019s more, ongoing vaccine safety is closely monitored through the U.S. Department of Health and Human Services\u2019 Vaccine Adverse Event Reporting System (VAERS<\/a>) and the Centers for Disease Control and Prevention\u2019s Vaccine Safety Datalink (VSD<\/a>). Potential safety signals are also monitored by each manufacturer.<\/p>\n

For example, Kedl says, U.S. and European monitoring helped officials quickly spot rare cases of blood clotting<\/a> from the adenovirus-based Johnson & Johnson COVID-19 vaccine, which ultimately led to its pause and phase-out. That\u2019s despite the problem having occurred, on average, fewer than four times per million doses.<\/p>\n

\u201cBased on a handful of cases across millions and millions of doses given within a couple of weeks, they figured it out because of those safety-monitoring systems,\u201d Kedl said.<\/p>\n

The moral burden of misinformation <\/strong><\/h2>\n

Kedl and colleagues share frustration with how the messaging coming from some of the nation\u2019s top health officials fuels vaccine skepticism.<\/p>\n

Notions that the measles component of the MMR vaccine wears off quickly are false. Its protection is durable over decades<\/a>.<\/p>\n