Spacing Out Vaccines? No Evidence Supports Candidates' Ideas

A young boy receives a vaccination from his doctor.
(Image credit: Oksana Kuzmina/

There is no evidence that supports spacing out childhood vaccines — which two Republican candidates for president suggested in last night's presidential debate — instead of following the recommended schedule, experts say.

"I am totally in favor of vaccines, but I want smaller doses over a longer period of time," Donald Trump, one of the candidates for president, said at the debate.

Candidate and retired pediatric neurosurgeon Ben Carson responded by saying, "We have extremely well-documented proof that there is no autism associated with vaccinations," he said.

Carson went on, however, to agree with Trump about spacing out vaccines. "But it is true that we are probably giving way too many in too short period of time, and a lot of pediatricians now recognize that, and I think are cutting down on the number and the proximity in which those are done" he said.

Candidate Senator Rand Paul, an ophthalmologist, also agreed.

"I'm for vaccines, but I'm also for freedom," he said. "Even if the science doesn't say bunching them up is a problem, I ought to be able to spread my vaccines out a little bit at the very least."

But not only is there no evidence that spacing out childhood vaccines is good for children's health, but the evidence actually suggests quite the opposite, Dr. Paul Offit, chief of the division of infectious diseases at the Children's Hospital of Philadelphia, told Live Science.

There's evidence that supports not spacing out vaccines any further than they are scheduled under current recommendations, Offit said. [5 Dangerous Vaccine Myths]

"To suggest that you make your own schedule is dangerous," he said. "That's why we saw the measles outbreak in Disneyland this year" he said — because parents chose to delay vaccinating their children.

Spacing out the current vaccine schedule leaves children susceptible to diseases for longer periods of time than they need to be, Dr. William Schaffner, a professor of preventive medicine at Vanderbilt University, told Live Science.

Moreover, spacing out vaccines is an unproven way to vaccinate: No one's ever tested it, so scientists don't know how well it works or how safe it is, he said.

And it's been documented that a vaccine that is pushed back can become a vaccine that is never received, Schaffner added.

Although some parents have raised concerns that an infant's immune system may not be able to "handle" the numerous immunizations children are scheduled to receive, there is no evidence that shows this is true, Schaffner said. "That's been shown clearly not to be the case," he said. "It's safe and effective."

Whenever a new vaccine is added to the existing schedule, scientists are required to prove to the Food and Drug Administration that the new injection doesn't interfere with other vaccines, Offit said. "It's well-tested," he said.

"The immunization schedule is based on an elaborate amount of scientific research," Schaffner said. "It's designed to be maximally effective and maximally safe."

Shortly after the debate, the American Academy of Pediatrics released a statement that read, in part, "There is no 'alternative' immunization schedule. Delaying vaccines only leaves a child at risk of disease for a longer period of time; it does not make vaccinating safer."

Follow Live Science @livescience, Facebook & Google+. Originally published on Live Science.

Sara G. Miller
Staff Writer
Sara is a staff writer for Live Science, covering health. She grew up outside of Philadelphia and studied biology at Hamilton College in upstate New York. When she's not writing, she can be found at the library, checking out a big stack of books.