President Donald Trump‘s latest executive order calls for splitting the measles, mumps and rubella, or MMR, vaccine into three separate shots – but doctors and other experts say that effort has no scientific basis and is unlikely to get off the ground. 

Trump on Monday said without evidence that the vaccine could be “quite lethal” in its combined form, even though the shot has repeatedly been proven safe and effective across large-scale studies. Experts called that claim “completely false” and said there is no scientific data showing benefits of separating the shot. 

Splitting the vaccine would also come with “significant logistical limitations,” and having three standalone shots that require multiple doctor’s visits could result in more delayed or missed vaccinations among kids, Neil Maniar, a public health professor at Northeastern University, told CNBC. 

“They’re not solving a problem here. They’re creating a new one,” Maniar said. “Based on false scientific rationale and political ideology, they’re changing something that works into something that we have no idea what it will do.” 

The U.S. has already seen a decrease in the share of parents who are willing to use the MMR shot to vaccinate their children, which has contributed to the recent resurgence in U.S. measles cases, Dr. Andrew Racine, president of the American Academy of Pediatrics, told reporters on Wednesday. The U.S. has logged its highest number of measles cases in decades this year.

Trump’s rhetoric and recommendations could also further undermine the public’s confidence in the safety of the MMR vaccine, said William Moss, a pediatrician and epidemiological professor at Johns Hopkins University.

Roughly 9% of parents report either skipping or delaying the MMR vaccine for their children, according to a 2025 survey conducted by health policy organization KFF and the Washington Post. It’s unclear how that compares to previous years. 

It’s also not clear where Trump initially got the idea to split the shots, but some experts say it can likely be traced to a British gastroenterologist, Andrew Wakefield. He is an anti-vaccine advocate who published a paper in 1998 claiming to show a connection between MMR vaccines and an increase in autism. That paper has since been retracted, and Wakefield was removed from the U.K.’s medical register.

Manufacturers of the MMR vaccine – Merck and GSK – seem to have little incentive to develop standalone shots, which would take significant time and resources away from their other crucial work toward treating and finding cures to other diseases. Those vaccines would likely reach the market long after Trump’s term ends. 

“I don’t see any world in which…

President Donald Trump on Monday signed an executive order backing fewer routine vaccines for kids, calling to whittle down the number of recommended childhood shots to 11 while falsely tying immunizations to autism.

The order builds on the Trump administration’s efforts to reshape the childhood shot schedule under Health and Human Services Secretary Robert F. Kennedy Jr., a longtime vaccine skeptic. 

“This updated recommendation finally aligns the United States with other advanced and developed nations around the world,” Trump said during a briefing on Monday. “More importantly, it aligns us with common sense and knowledge.”

He also falsely tied vaccines to autism, suggesting multiple times that rising rates of childhood shots have led to an increase in autism diagnoses. Decades of scientific evidence has shown no link between autism and childhood vaccines.

He also called for splitting the combination measles, mumps and rubella, or MMR, vaccine into three separate single-disease shots.

“The MMR we want to have separate visits, separate times. The vaccine being broken into three separate single doses and vaccines being administered in separate visits,” Trump said.

The order also directs the Department of Justice to investigate where states are in violation of exemptions for childhood vaccine mandates, including parental authority and disability accommodations as well as religious and medical reasons.

It’s not the first time the administration has taken aim at the MMR vaccine and the related MMRV shot, which always inoculates against chickenpox. Last year, a key vaccine advisory panel to the Centers for Disease Control and Prevention also weakened recommendations for the MMRV shot for children under 4.

But some health experts say that splitting up the shot raises the chance of missed appointments and skipped immunizations because it requires more doctor visits. Speaking to reporters after signing the order, Trump acknowledged it may be hard for some parents to take a child to the doctor multiple times, but argued it would be worth it.

“It’s inconvenient, it’s five stops, but it’s something that I think will have a huge impact on autism,” he said.

There is no scientific evidence that combining the shots leads to higher autism risk.

Asked if he has any concerns about parents being able to afford multiple co-pays for doctor’s visits, Trump said “we’re going to work with the families” to help them afford the costs, without saying specifically how.

The White House also confirmed that changes in vaccine recommendations would not change insurance coverage for the shots.

Trump’s executive order comes as the U.S. logs its worst year for measles infections in decades….

The U.K. will ban social media from offering services to under-16s, Prime Minister Keir Starmer announced on Monday, as governments around the world face mounting pressure to ensure child safety online.

The ban could include platforms like Snapchat, TikTok, YouTube, Instagram, Facebook and X. The first set of regulations could take effect as soon as spring 2027. 

The U.K. plans to model its approach on landmark Australian legislation passed late last year, but the country will go further by introducing additional restrictions on features deemed particularly harmful to children.

These include blocking livestreaming and communication with strangers for users under 16, while similar protections will be enabled by default for 16- and 17-year-olds. The government is also considering overnight curfews and measures to limit infinite scrolling for minors.

“We’re going further than any country in the world by banning social media for under-16s and putting wider protections in place to give kids their childhood back,” Starmer said in a statement.

Social media is making children unhappy and is designed to be addictive, Starmer said at a press conference. He didn’t make the decision lightly and it will not be cost-free, he said, noting that social media had brought some benefits to young people.

The ban comes after the U.K. has seen a number of high-profile cases related to social media and self-harm.

Critics argue that blanket bans are ineffective and will simply stifle access to age-appropriate experiences with parental controls, and that young people will find a way around the ban. For example, a BBC report found that downloads of VPNs in Australia, which hide users’ locations to avoid country-specific restrictions, increased before the ban.

A YouTube spokesperson told CNBC it’s invested in “expert-led, age-appropriate experiences and default protections for teens” and that “blanket bans push kids out of such curated, supervised, beneficial experiences and towards anonymous, less safe services.”

“Tech companies have had countless opportunities to keep children safe, yet they have failed to act. That is why we are taking power away from the tech giants and putting it back in parents’ hands,” said Technology Secretary Liz Kendall.

CNBC has reached out to the parent companies of the social media platforms that could be affected for comment.

Starmer said he spoke to U.S. President Donald Trump on Saturday and would see him again this afternoon for the G7 meeting, and that they would discuss “this and many other issues.”

— CNBC’s Kai Nicol-Schwarz and Sawdah Bhaimiya contributed to this report.