Acting CDC Director Calls for MMR Vaccine to Be Split Up Into 3 Separate Jabs

The CDC website also states that getting multiple vaccines at the same time has been shown to be safe.

Published: 10/9/2025, 5:00:55 PM EDT

Acting CDC Director Calls for MMR Vaccine to Be Split Up Into 3 Separate Jabs — Xerius Jackson, age 7, gets an MMR vaccine at a vaccine clinic put on by Lubbock Public Health Department in Lubbock, Texas, on March 1, 2025. (Jan Sonnenmair/Getty Images)

Combine childhood vaccines or separate? That seems to be the question.

In a follow-up to President Donald Trump's call that the combined measles, mumps, and rubella vaccine (MMR) should be split into three separate injections, Jim O'Neill, the acting director of the Centers for Disease Control and Prevention (CDC), has echoed that directive saying in an X post this week; "I call on vaccine manufacturers to develop safe monovalent vaccines to replace the combined MMR and 'break up the MMR shot into three totally separate shots.'”

A glance at the CDC's own website shows that the MMR vaccine is still recommended as it has been since being introduced in 1971.

The CDC website also continues to promote the safety of the three-in-one MMR vaccine, saying that "Scientific data show that getting several vaccines at the same time does not cause any chronic health problems." There is no more information from O'Neill on this announcement and it remains unclear if the MMR vaccine will, in fact, be split into three. A statement from Andrew Nixon, a spokesman for the Department of Health and Human Services, which is led by Secretary Robert F. Kennedy Jr., said "standalone vaccinations can potentially reduce the risk of side effects and can maximize parental choice in childhood immunizations."

While Nixon did not explain further about how the standalone vaccinations can reduce side effects risks, NTD reached out to him on Thursday seeking additional information and clarification and we received the following reply from DHS press secretary Emily Hilliard: "Secretary O'Neill agrees with President Trump that immunizations for measles, mumps, and rubella would be best administered as three separate vaccines." The remainder of her reply was a repeat of the above statement Nixon gave the press.

Per the CDC: "A number of studies have been done to look at the effects of giving various combinations of vaccines, and when every new vaccine is licensed, it has been tested along with the vaccines already recommended for a particular aged child. The recommended vaccines have been shown to be as effective in combination as they are individually."

The CDC website also states that getting multiple vaccines at the same time has been shown to be safe.

O'Neill's social-media statement follows Trump's Sept. 22 press event, where he discussed the dangers of Tylenol for pregnant women, before addressing vaccine concerns.

As Trump said at the time: “They pump so much stuff into those beautiful little babies. It’s a disgrace,” he said. “It looks like they’re pumping into a horse. You have a little child, little fragile child, and you get a vat of 80 different vaccines, I guess, 80 different blends, and they pump it in.”

A look at the Cleveland Clinic's website, which makes childhood vaccine schedule recommendations, suggests that children receive their first MMR dose at the age of one. And the second MMR round at the age of four.