Trump wants to split the MMR vaccine into separate shots. Experts say it’s a bad idea

President Donald Trump has signed an executive order intended to overhaul American vaccine policy by requiring the MMR vaccine to be administered as three individual shots. The directive also suggests that all childhood immunizations should be given during separate medical appointments rather than in combined visits.

The move has drawn immediate fire from the medical community. Immunologists and pediatric experts argue that spreading out vaccinations is unscientific, costly, and serves only to make the process more difficult for parents while increasing the risk of children missing vital doses.

Scientific Pushback and Safety Concerns

The United States has utilized the combined MMR shot for over half a century. The CDC states clearly on its website that "no published scientific evidence shows any benefit in separating the combination MMR vaccine into three individual shots."

Dr. Stanley Plotkin, a renowned vaccine developer, described the new recommendations as "stupid" and "unscientific." He warned that the change will likely result in a surge of diseases that were previously under control, as decreasing vaccine coverage weakens herd immunity.

Trump defended the decision by citing long-debunked claims regarding a link between vaccines and autism, despite an avalanche of global research proving no such connection exists. He also incorrectly described the volume of vaccines as being "the size of a bottle of soda," when a standard MMR dose is actually about one-tenth of a teaspoon.

Logistical and Manufacturing Hurdles

Implementation of the order faces significant practical barriers. Currently, there are no individual vaccines for measles, mumps, or rubella available for purchase in the U.S. Merck, the primary manufacturer, stopped supplying single-disease shots in 2008 because the combination shot is safer and more efficient.

Merck stated that returning to separate doses would not be simple, noting it could take up to 10 years to meet FDA safety and efficacy standards for new production lines. This leaves the administration's 90-day deadline for a new plan, led by HHS Secretary Robert F. Kennedy Jr., looking highly ambitious.

Lessons from Japan

The administration pointed to Japan as a model for separate shots, but health experts note that Japan's experience actually serves as a warning. When Japan moved to single-component shots in the 1990s, measles infections spiked, leading to an outbreak of 265,000 cases.

Furthermore, data from Japan showed that even after switching to separate injections, autism rates continued to rise, further disproving the theory that combined shots are a contributing factor. Japan has recently moved back toward trivalent vaccines to control ongoing mumps outbreaks.

Virologist Dr. Angela Rasmussen noted that the current U.S. schedule is the result of decades of safety monitoring. She warned that by playing on parental emotions, the new policy may lead to accidental delays that could result in child fatalities from flu or measles.