No link between MMR vaccination before age 2 and autism, large US study suggests - CIDRAP

Share Copied to clipboard Samara Heisz / iStock A national retrospective cohort study of more than 2.5 million children found no association between receiving the measles, mumps, and rubella (MMR) vaccine before age 2 years and having an autism diagnosis.  “These results reinforce existing evidence supporting the safety of MMR vaccination,” wrote the authors, from the University of Washington.  Some people worry that MMR vaccines cause autism, despite a lack of evidence supporting this theory. This paper is the latest to examine the MMR vaccine and autism by looking at the timing of the vaccine.  Using the Cosmos electronic health record database, researchers looked at the records of more than 2.5 million children who had linked parent information from January 2015 through December 2024. The scientists followed the children until age 8 or their last doctor’s appointment before the study end date.  Receiving the first MMR vaccine dose from ages 11.5 to 24 months was not associated with an increased likelihood of having an autism diagnosis.  It’s been a record-breaking year in the United States for measles, with the Centers for Disease Control and Prevention (CDC) reporting 2,371 cases this year, with 93% of these infections occurring in unvaccinated people. This is the highest number of measles cases since 1991.  These results reinforce existing evidence supporting the safety of MMR vaccination. In an interview with CNN’s Dana Bash yesterday, Secretary of Health and Human Services Robert F. Kennedy Jr. said he is not responsible for the ongoing measles outbreak, despite years of saying childhood vaccines cause autism. “I’ve never questioned the efficacy of the MMR vaccine,” he said.  Kennedy also encouraged parents to vaccinate their children. “A measles vaccine is effective,” he said. “It stops measles in about 97% of the cases.”  The Ebola outbreak in the Democratic Republic of the Congo (DRC) is entering its third month as the second-deadliest in history and the largest Ebola outbreak ever recorded in the DRC. As of yesterday, DRC officials reported 3,695 cases and 1,623 deaths.  The deadliest outbreak in history remains the 2014-2016 West African outbreak, which resulted in more than 11,000 deaths. The current outbreak is caused by a strain of Ebola virus, Bundibugyo, that has only caused three outbreaks in history and has no targeted therapeutics or vaccines.  In a new Disease Outbreak News report from the World Health Organization (WHO), the agency says the outbreak is intensifying, and the crude case fatality ratio (CFR) now stands at 44%. Transmission rates are increasing, and in the last week of July, the highest weekly number of reported cases (567) and deaths (296) to date were recorded, the WHO said. There have been 151 cases among healthcare workers, including 44 deaths (CFR 29%). Ituri remains the most affected province, accounting for 88% of all confirmed cases and 82.6% of reported deaths nationwide. About 75.5% of case contacts are under active follow-up in Ituri.  “A substantial scaling up of response activities is needed to get ahead of the outbreak,” the WHO warned.  Today the Associated Press reported an increased maternal mortality rate in the outbreak regions, as women are skipping prenatal care and births attended to by medical professionals because of fears of contracting Ebola in medical centers.  Noemi Dalmonte, deputy country representative of the United Nations Population Fund inthe DRC, told the AP that an average of six women a week were dying due to childbirth complications, double last year’s average.  Vaccine maker Moderna said late last week that a phase 3 trial for its investigational mRNA norovirus vaccine candidate did not meet statistical criteria for early success. “The trial is ongoing and remains blinded as the Company works toward enrolling an additional cohort,” the company said in an update on its second quarter 2026 financial results. The phase 3 trial for mRNA-1403, a trivalent norovirus vaccine, launched in September 2024. The company aims to recruit up to 20,000 participants ages 60 years and older and an additional 5,000 aged 18 to 59 from countries in both the northern and southern hemispheres to assess the vaccine’s ability to protect against moderate to severe illness caused by norovirus. But the study has faced a clinical hold over a single case of Guillan-Barre syndrome and challenges with recruiting patients. According to reporting by Endpoint News, company officials said in a conference call that additional patients are needed because there haven’t been enough infections to adequately assess the efficacy of the vaccine. Norovirus is the leading cause of vomiting and diarrhea from acute gastroenteritis among Americans of all ages and causes 58% of all foodborne illnesses in the United States, according to the Centers for Disease Control and Prevention. An estimated 2,500 reported norovirus outbreaks occur in the United States each year. The findings reinforce existing evidence of the safety of MMR vaccination, the authors say. Cyclosporiasis cases in a second outbreak not connected to lettuce continue to climb nationwide. Only 9 of the 400 bills became law, and no state eliminated childhood immunization requirements. A total of 1.6 million dozen eggs shipped to six states have been recalled. The response to the current large outbreak is a communications failure, not a failure of the investigation. The nation’s former top infectious disease expert refused to answer questions from Sen. Rand Paul and others who accused him of misleading the country about the origins of COVID. The findings don’t confirm that the fatal disease is a threat to people but do offer important clues to what infection might look like in humans. Infrequent communication from the federal government about the large Cyclospora outbreak caused a “big black hole for information.” Some Republican committee members allege that Fauci had no right to invoke the Fifth Amendment, because a pardon protects him from criminal prosecution. But some experts say it will impede the US’s ability to address infectious disease threats and respond to outbreaks.