"Does It Really Cause Autism?" Anxious Parents and "Vaccine Conspiracy Theories" Shaking Public Health

1. Key Details of the Executive Order Signed by Trump

On August 10, President Trump signed an executive order in the Oval Office with Health and Human Services Secretary Robert F. Kennedy Jr. looking on. The order reduces the list of recommended childhood vaccine-preventable diseases from 18 to 11, removing vaccines for hepatitis, COVID-19, and influenza from the "recommended for all children" list. At the same time, it recommends splitting the combination MMR vaccine into three separate single-disease shots, each to be administered at separate medical visits. This measure follows a previous court ruling blocking Secretary Kennedy's attempt to alter the vaccine schedule, and the executive order is likely to face legal challenges.

2. "Can Be Quite Lethal" – Trump's Unfounded Claim

Regarding the reason for splitting the combination MMR vaccine, Trump said, "If you give them together, it seems like it can be quite lethal, and if you give them separately, it doesn't seem lethal at all." When asked by a reporter for his basis, he replied, "Some people say that." According to the U.S. FDA, a single dose of the MMR vaccine is 0.5 milliliters, and the CDC states that the vaccine is "very safe."

3. Why Splitting MMR Shots Is Problematic

The CDC explicitly states that there is no scientific evidence that splitting the MMR combination vaccine into three separate doses offers any benefit. The American Academy of Pediatrics (AAP) projects it would take 10 years to develop separate single-disease vaccines, and single vaccines for measles, mumps, and rubella currently do not exist in the United States. Experts point out that spacing out vaccinations increases the risk of a child contracting a disease during the gap and raises the likelihood of missed doses due to requiring multiple doctor visits. Dr. William Schaffner of Vanderbilt University School of Medicine said, "It makes it harder for parents and healthcare providers to keep track of schedules and increases costs, with absolutely no scientific benefit."

4. Backlash from the Medical Community

Dr. Andrew Racine, president of the American Academy of Pediatrics, criticized Trump's executive order as "dangerous," saying it was "not based on gold-standard science." He stated, "Delaying or skipping shots is risky, especially as measles continues to spread and children go back to school." Vaccine manufacturer Merck also warned, "There is no published scientific evidence showing benefit to splitting the MMR vaccine, and requiring multiple doctor visits increases the risk of delayed or missed vaccinations."

5. Criticism Arises Even Within the Republican Party

Republican Senator and physician Bill Cassidy directly criticized the move, saying, "This executive order is wrong. The president does not have the expertise to make these changes. Vaccines are overwhelmingly safe and effective, and they do not cause autism." Cassidy's remarks drew even more attention because he cast a decisive vote in favor of Secretary Kennedy's Senate confirmation. Secretary Kennedy emphasized, "I have never questioned the efficacy of the MMR vaccine," adding, "We are trying to give parents a choice, not ban vaccinations."

6. Vaccine-Autism Link: What Does the Science Say?

Decades of research have established that there is no link between vaccines and autism. A large-scale Danish study published in 2019 tracked more than 657,000 children and found no evidence that the MMR vaccine triggers or causes autism. Trump claimed that the current autism rate in the U.S. (1 in 31) is likely due to the number of vaccines children receive in their first year of life, but this directly contradicts decades of scientific research.

7. Call to Replace Aluminum

The executive order also called for developing substitutes for aluminum in vaccines. However, the American Academy of Pediatrics states that there is no evidence showing that trace amounts of aluminum salts in vaccines pose a significant health risk. Aluminum salts naturally occur in soil, water, and food, and have been used in vaccines for decades. They also serve to boost immune responses, allowing smaller amounts of vaccine to be effective.

8. Warnings from International Health Organizations

The Centre for Health Protection in Hong Kong warned that "changing vaccination schedules without reliable scientific data or medical research could pose serious and irreversible public health risks to children." World Health Organization (WHO) spokesperson Tarik Jašarević stated, "Vaccine recommendations are based on over 60 years of research by WHO, national authorities, and independent expert groups. What we put forward is grounded in science, and we hope all countries utilize the best available scientific evidence."

9. The Reality of the 2026 Measles Crisis

As of July 2026, the number of confirmed measles cases in the U.S. stands at 2,318, higher than any full year since measles elimination was declared in 2000. While 2025 was already a record year with 2,289 cases, 2026 has already surpassed it. Over 93% of those infected were unvaccinated. Under these circumstances, concerns are growing that an executive order adding complexity to the MMR vaccination schedule could worsen delays and missed shots.

10. Connection to South Korea: Importation Risks and Disinformation Spread

The surge in measles cases in the United States is not irrelevant to South Korea. Given the annual volume of air travel between South Korea and the U.S., a decline in U.S. vaccination rates could translate into an increased risk of imported measles cases domestically. Indeed, when measles outbreaks occurred in the U.S. and Europe in 2019, imported cases were reported in South Korea in succession. Another risk is the spread of information. Statements by Trump and Kennedy tend to be rapidly translated and disseminated across Korean YouTube channels and online communities, echoing patterns seen during the COVID-19 pandemic when vaccine hesitancy messages originating in the U.S. fueled domestic vaccine hesitancy. South Korea's MMR vaccination rate currently stands at 97–98%, among the highest in the world, and the Korea Disease Control and Prevention Agency (KDCA) has no plans to alter the national immunization schedule, which remains grounded in WHO guidelines and local epidemiological data. However, the situation in the U.S. serves as a precedent demonstrating how quickly a public health system can be reversed by political willpower alone.

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Trump's executive order on vaccines conflicts directly with scientific consensus. While framed under the rationale of "giving parents a choice," the medical community warns that this choice could lead to a resurgence of preventable diseases like measles. With the worst measles outbreak in 35 years currently underway, the impact of this executive order on the health of American children will manifest in data within months. And that data is something the entire world, including South Korea, must closely observe.


Deep Dive Q&A
Q1. Why is splitting the MMR vaccine into three separate doses difficult to implement?

A. Currently, separate single-disease vaccines for measles, mumps, and rubella do not exist in the United States. Developing single-disease vaccines would require pharmaceutical companies to conduct new clinical trials, a process the American Academy of Pediatrics projects could take 10 years. The CDC explicitly states that there is no scientific evidence showing any benefit to splitting the combination vaccine. In short, the executive order effectively demands products that do not even exist.

Q2. Where did the claim linking vaccines to autism originate?

A. In 1998, British doctor Andrew Wakefield published a paper claiming a link between the MMR vaccine and autism. However, after data falsification was exposed, his medical license was revoked in 2010 and the paper was retracted. Since then, dozens of large-scale studies have repeatedly confirmed that no link exists, notably a 2019 Danish study tracking 657,000 children. This baseless claim continues to resurface because it serves as a powerful narrative that taps into parents' anxieties, a pattern also observed in South Korea during controversies over COVID-19 vaccines.

Q3. Could the measles situation in the U.S. directly impact South Korea?

A. It is possible. Measles is a highly contagious virus where herd immunity breaks down if vaccination rates drop below 95%, allowing a single imported case to lead to community transmission. While South Korea's vaccination rate currently stands in the safe zone at 97–98%, increased imported cases from the U.S. and a spread of vaccine hesitancy domestically could weaken that shield. The Korea Disease Control and Prevention Agency maintains fever surveillance for arriving travelers and a suspected measles reporting system, advising anyone developing fever or rash after traveling to the U.S. to report it immediately.
※ Please note: This article was translated by AI and may contain errors.