Jim O’Neil, the acting director of the CDC and deputy health secretary, called for the measles mumps rubella vaccine to be separated into three separate shots, echoing demands the president has made several times. 

In response to a Truth Social post that was then tweeted out on X, O’Neil thanked President Donald Trump for his ‘leadership’ and wrote: ‘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,” quoting Trump’s original post. 

In the original Truth Social post, Trump wrote: ‘BREAK UP THE MMR SHOT INTO THREE TOTALLY SEPARATE SHOTS (NOT MIXED!), TAKE CHICKEN P SHOT SEPARATELY, TAKE HEPATITAS [sic] B SHOT AT 12 YEARS OLD, OR OLDER, AND, IMPORTANTLY, TAKE VACCINE IN FIVE SEPARATE MEDICAL VISITS!’ 

Trump first made comments on the subject during a press conference last month in which he linked acetaminophen, known as Tylenol, to autism. 

The president urged parents to get the measles, mumps and rubella (MMR) shots, normally delivered as a three-in-one vaccine, separately in multiple doctors visits.

It is not clear whether it is possible to get the measles, mumps and rubella vaccines separately in the US, with the CDC saying that only the combined versions are available. The combined shot was approved by the FDA in 1971. 

The CDC says there is no published scientific benefit to support separating the shots. Officials stress that giving the vaccines together means children are protected sooner, endure fewer doctor’s visits and less trauma, while parents save both time and money. 

Health and Human Services Deputy Secretary and acting CDC Administrator Jim O’Neil is pictured above last month speaking to the organ transplant system 

Trump added during the press conference in September that children should also get the varicella, or chickenpox, vaccine separately, as this can also be given as a combination vaccine with the MMR. 

And Trump said parents should not get their children vaccinated against hepatitis B until they are 12 years old.

The CDC’s Robert F Kennedy Jr-appointed vaccines advisory panel had previously voted for the agency to no longer recommend that the MMR and varicella vaccines be given in the same shot to children aged four years and under. 

Instead, it said that the MMR and varicella vaccines should be administered separately.

Before the announcement, the CDC was already recommending that the MMR and varicella shots be administered separately unless a parent requests the combined version.

Studies show a slightly higher risk of febrile seizures in children who receive the combined shot as a first dose compared to those who receive the two shots separately on the same doctor’s visit. 

Also on Monday, the CDC updated its adult and child immunization schedule to ‘apply individual-based decision making to Covid-19 vaccination.’

And the CDC reiterated its recommendation that toddlers get the chickenpox vaccine separately from the MMR shot. 

Before the measles vaccine, the disease infected 3 to 4million people, caused 48,000 hospitalizations and 400 to 500 deaths every year.

The hepatitis B virus can cause a chronic infection in the liver that cannot be cleared and can lead to scarring of the organ and cancer.

It is a particular concern in infants, with the CDC estimating that 90 percent of unvaccinated children who catch the virus develop a chronic infection.

In the US, the hepatitis B vaccine is recommended for all children at birth, with two other doses at one to two months of age and six to 18 months of age.

It is only recommended for children aged 12 years or over as a catch-up dose and to avoid a chronic, lifelong infection with the disease.

It is not clear whether there would be a benefit to delaying vaccination against hepatitis B until the age of 12 years, although this could raise the risk of a child being infected with the virus and suffering from complications.

An estimated 640,000 people in the US are infected with chronic hepatitis B, while nearly 2,000 deaths are linked to the virus every year. The virus is spread via needles and syringes and contact with infected blood or bodily fluids. It can be passed from mother to child during childbirth.