“This is based on what I feel.” That was the president last September, explaining why he wanted the measles, mumps and rubella (MMR) vaccine broken into three separate shots. On Monday, he signed an executive order instructing exactly that.
Four decades in intensive care have taught me what a feeling costs once it becomes national policy. Children will be hospitalized who did not need to be. Some of them will die. No one can name those the vaccine has saved, because prevented harm is invisible by definition, and that invisibility is what makes preventive medicine easy to dismantle and hard to defend.
The order rests on a single complaint, stated in the White House’s own fact sheet: American children are recommended more vaccine doses than children anywhere in the developed world, 84 doses across 57 injections by 2024 against 23 doses in seven injections in 1980. Section 2 of Monday’s executive order directs that the MMR be given as three single-disease shots, and that “to the maximum extent feasible, all childhood immunizations should be administered at separate medical visits”. Not only the MMR: every childhood immunization.
No evidence supports the spacing. The most thorough review of the American schedule ever conducted, by the Institute of Medicine in 2013, found no safety signal and no case for spreading doses out; a delayed-schedule trial, if held, could not ethically be run, because delay only lengthens the time a child is unprotected.
The president and Robert F Kennedy Jr, his health secretary, returned repeatedly to autism as the order was signed. A study in 2019 followed 657,461 Danish children and found no association between MMR and autism. Last month, researchers examined 2.56 million American children and found none between the timing of a first MMR dose and a later diagnosis. Those studies were designed to answer whether vaccines are the cause, and they have answered it. They are not.
Under Trump’s order, the number of diseases every child is recommended to be protected against falls from 18 to 11. Seven are gone: hepatitis A, hepatitis B, rotavirus, influenza, Covid-19, meningococcal disease and RSV. Some are now recommended only for children already at high risk. The rest are moved to what the order calls “shared clinical decision-making”.
Hepatitis B is the clearest example of the danger here. An infant infected at delivery has roughly a 90% chance of chronic infection, and the dose given in the first hours of life prevents about three-quarters of that transmission. Meningococcal disease kills 10% to 15% of those it infects even when antibiotics start promptly, and up to one in five survivors is left with deafness or an amputated limb. RSV was the leading cause of hospitalization among American infants until universal immunization began in 2023; in the first season with those products widely available, hospitalization among infants under eight months fell by about 43%.
This is a country that ended domestic polio, helped the world eradicate smallpox, and whose National Institutes of Health helped engineer the stabilized spike protein behind the first Covid vaccines. Its childhood immunization schedule has now been rewritten by a man with no medical training, who touted his own instinct. We have seen that instinct applied to medicine: in April 2020, shown data on disinfecting surfaces, he asked at a televised briefing whether the same might be done inside the body, “by injection inside or almost a cleaning”.
A president is entitled to be a layperson. Most are. The question is what a layperson’s instinct is doing where evidence belongs, and Monday’s answer is that it now sits there formally, with the federal government behind it.
At the moment, the splitting instruction also cannot be carried out, and the order quietly concedes it, conditioning it on single-disease products becoming domestically available. None exist. Merck stopped making them in 2008 and told federal advisers in 2009 that it would not resume, at the urging of pediatricians who warned it would mean more needles and longer vulnerability. Restoring them would take years.
Suppose they existed. Federal survey data describe who is unable to complete a multidose series: uninsured, low-income, renting, recently moved, more than one child at home. In a county with no pediatrician, one well-child visit already costs half a day of wages. Ask for three. Families with paid leave and a reliable car will manage it.
There is no margin left to spend. Kindergarten MMR coverage is 92.5%, under the 95% needed to interrupt transmission, with exemptions at a record of 3.6%. There has been more measles this year than in any of the past 35 years, and in November the Pan American Health Organization decides whether the country still qualifies as having eliminated it.
What reaches an adult intensive care unit is the far end of these decisions. I spent the pandemic watching unvaccinated patients die of an illness they had been offered protection against. This year, our neurocritical care conference reviewed a child left with profound and permanent brain damage by the seizures of measles encephalitis. There is a vaccine that has prevented it since before I entered medical school.
The provision that will outlast the argument was written for lawyers. School entry rules are state law, and no president can rewrite them. Section 4 instead directs the attorney general to pursue legal action against state laws that conflict with obligations to provide religious and medical exemptions. That is the Department of Justice aimed at the last enforceable layer of protection American children have.
The order does not have to persuade a single parent. It only has to remove a recommendation, add visits, and point a government lawyer at a state legislature. A feeling cannot be tested, and it cannot be proven wrong. The children it reaches cannot be counted.
