Splitting Up the Combination Vaccines

President Trump announced on Sept. 18, 2026 that his administration plans to recommend that certain childhood vaccines be split up into separate shots. The policy proposal is apparently a follow-up to an Executive Order the President signed on Aug. 10 that calls for recommending the number of diseases for which children should be vaccinated be reduced from 17 to 11, including measles, mumps, rubella, diphtheria, tetanus, pertussis, polio, Haemophilus influenzae type B, pneumococcal disease, human papillomavirus, and varicella.^{1 2 3} Trump said:

Instead of a child going in and having a tremendous amount of different vaccines pumped into a big proportion of the body … we’re going to recommend that they do five doses marked one, two, three, four, five and that they be given in six-month intervals, so that a small amount of the vaccine gets pumped into the body.^{1 2}

MMR Could Be First to Be Targeted

A likely combination vaccine that could be separated into individual shots would be the live attenuated MMR vaccine, a three and four-vaccine combo shot in the form of the MMR (measles, mumps, and rubella) and MMRV (measles, mumps, rubella, and varicella) vaccines.

Last month’s Executive Order actually specified that the MMR vaccine be broken up and be administered as separate shots. The MMR, either Merck’s M-M-R II product or GSK’s Priorix, are recommended for children 12-15 months old (first dose) and 4-6 years old (second dose). Breaking up the vaccine would mean giving three shots (one each for measles, mumps, and rubella) instead of one combo shot for the first dose and three shots again instead of the combination MMR shot for the second dose.^{3 4}

There is another combo shot on the U.S. Centers for Disease Control and Prevention’s (CDC) childhood vaccination schedule—the DTaP (diphtheria, tetanus, and acellular pertussis). There are two DTaP combo vaccines licensed in the United States—Sanofi Pasteur’s Daptacel and GSK’s Infanrix. The DTaP shot is recommended to be given five times. The first shot at two months of age, the second at four months, the third at six months, the fourth between 15 and18 months, and the fifth between 4 and 6 years. Breaking up the vaccine would mean, again, giving three shots (one each for diphtheria, tetanus, and pertussis) instead of one combo shot for each of the five doses.^{5 6 7 8}

There are five other combo vaccines licensed in the U.S. that include the DTaP—Kinrix, Quadracel, Pediarix, Pentacel, and Vaxelis. GSK’s Kinrix and Sanofi Pasteur’s Quadracel each add the inactivated poliovirus vaccine to make them four-vaccine combos. GSK’s Pediarix adds the hepatitis B and inactivated poliovirus vaccines, making it a five-vaccine combo. Sanofi Pasteur’s Pentacel adds the inactivated poliovirus and Haemophilus influenzae type b vaccines for another five-vaccine combo. Lastly, Merck/Sanofi Pasteur’s Vaxelis adds the inactivated poliovirus, hepatitis B, and Haemophilus influenzae type b vaccines for a whopping six-vaccine combo.⁹

There is also the Tdap (tetanus, diphtheria, and acellular pertussis) vaccine), and one dose is recommended for children between 11-12 years old.¹⁰

Safety of Combo Vaccines a Concern

Combination vaccines, particularly the combination diptheria-tetanus-pertussis and measles-mumps-rubella vaccines have been used for decades since the mid-20^th century. If vaccine manufacturers agree to produce separate vaccines and the CDC officially recommends their use, this policy shift would represent a major reversal in the growing trend toward the development of more and more combo shots containing multiple vaccines.

An article by guest writer Sheri Marino republished in The Vaccine Reaction noted, “While the CDC suggests that combination vaccines are safe, research shows there are more adverse events, such as febrile seizures, with combination vaccines than there are for single vaccines.” Marino added, “Research published in the New England Journal of Medicine revealed a significantly elevated risk of febrile seizures 8 to 14 days after administration of the MMR vaccine.”¹¹

Marino continued:

According to the CDC, pre-licensing data obtained from the Vaccine Safety Datalink, reveals the MMRV vaccine shows recipients were twice as likely to have febrile seizures than those injected with the MMR and Varicella vaccines separately. Another study conducted in Denmark published in the Journal of American Medical Association demonstrated that the 5 valent DTaP-IPV-HIB vaccine has been linked with increased febrile seizures.¹¹

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