US experts slam Trump's plan to split MMR into separate childhood shots

Washington,UPDATED: Aug 13, 2026 16:38 IST

Public health experts in the US have criticised an executive order by President Donald Trump that seeks to break up combination childhood vaccines, saying it would create major financial and logistical problems for parents, doctors and vaccine makers. The order calls for vaccines such as the measles, mumps and rubella, or MMR, shot to be given as separate injections, with appointments spaced out wherever possible.

Experts said the move has no scientific basis and would take years to put in place, if it happens at all. They said it would require companies to restart production of individual vaccines not sold separately in the US for decades, while also forcing parents to make far more trips to doctors and increasing the risk that children may miss doses before starting school.

Under the order issued on Monday, federal officials have been told to draw up plans within 90 days for splitting the MMR vaccine and spacing out other childhood immunisations. But pharmaceutical scientists and former regulators said carrying out those changes would likely take years and cost drugmakers tens of millions of dollars in fresh studies and new manufacturing facilities.

At present, there are no individual vaccines in the US for measles, mumps or rubella. All vaccines approved by the Food and Drug Administration for those viruses are combination shots, and the three-in-one MMR approach has been standard in the country since the early 1970s. Dr Jesse Goodman, a former FDA vaccine chief, said companies would need to carry out large studies to show that any new individual shots produce immune responses in children similar to current vaccines. They might also need to prove the safety of new facilities and procedures, since individual measles shots have not been widely produced in the US for about 50 years.

"The question is how much has changed since then and how comfortable will the FDA and the companies be relying on those comparisons?" said Goodman, now a professor at Georgetown University. Industry experts said designing, building and getting federal approval for new vaccine plants usually takes about five years. Goodman also said the FDA would have to review and license each unbundled vaccine separately, something he said has no precedent. "I don't think there's any comparable example of removing hugely effective public health measures that protect babies for no documented scientific reason," he said.

Individual shots for measles and related diseases are generally used in lower-income countries that cannot afford the MMR shot. Merck, GSK and the small number of other companies supplying childhood vaccines in the US only make the combination vaccine. In separate statements, Merck and GSK said they stood by the safety and effectiveness of their products, though neither discussed plans to split their shots. "To date, there has been no published scientific evidence that shows any benefit in separating the combination MMR vaccine into three individual shots," Merck said in an emailed statement.

Doctors also warned that the change would increase the burden on families and health providers. The MMR vaccine is now given in two doses, the first at the age of 1 and the second after age 4. Splitting it into three separate vaccines would mean six office visits. Spacing out other vaccines for pertussis and other infectious diseases could push the number of visits even higher. That would also increase the use of syringes and other medical supplies, while adding to costs and pressure on paediatricians who usually give the shots.

Studies in the US and elsewhere have shown that combination vaccines make it more likely that children will be fully protected against infectious diseases before they begin school. Dr Anna Durbin of the Johns Hopkins Bloomberg School of Public Health said there was no reason to move away from that system. "We do things that are less convenient and more expensive if there's a good reason to do it," she said. "There is no good justification for this. I think it's very bad public health policy." She added: "It's going to be less convenient, more expensive and you're going to have fewer people getting vaccinated." Durbin also noted that while Trump and Health Secretary Robert F. Kennedy Jr. have pointed to countries such as Denmark, which recommend slightly fewer vaccines than the US, breaking up combination shots would leave children in the US receiving more individual injections than those in comparable countries.

White House spokesman Kush Desai said the administration's efforts on the MMR vaccine "will give parents more options on timing and frequency for their children, which ultimately will increase vaccination rates for all three diseases". Even so, some experts said the order may not lead to meaningful change. Neither the White House nor the FDA can force drugmakers to develop and seek approval for new vaccines, and companies have little business incentive to do so. "They'd be competing against themselves, and there's no reason to do that," said Dr Paul Offit, a vaccine researcher at the Children's Hospital of Philadelphia and a former government adviser. He also noted that only state governments have the authority to require vaccinations for schoolchildren, while Trump's order merely asks states to consider changing their laws. "I think states will ignore this," Offit said. "I think that bottom line is that we don't need to look to Donald Trump for our medical advice." Overall, experts said the order would be difficult to carry out, costly for the healthcare system and families, and would replace long-used combination vaccines with a more complicated process without scientific support.

With PTI Inputs

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