Vaccines to prevent chickenpox and measles, mumps and rubella ready for a pediatric vaccination at a medical office in Denver. (Joe Amon/The Denver Post via Getty Images)

This week, President-elect Donald Trump met with Robert F. Kennedy Jr., a leading proponent of a scientifically discredited conspiracy theory that vaccines cause autism. Afterward, Kennedy said that he and Trump had discussed creating a commission on vaccines, which Kennedy would chair.

The United States already has a commission on vaccines. A top U.S. public health official said Friday that it relies on an array of medical, scientific and community experts to set policy on vaccines, and does so in an open and deliberative process.

The Advisory Committee for Immunization Practices (ACIP) was established more than 50 years ago by the surgeon general to provide expert advice to the Centers for Disease Control and Prevention and the secretary of the Department of Health and Human Services on the use of vaccines for children and adults.

In an interview, CDC Director Tom Frieden said the federal agency is ready to work with the incoming Trump administration to protect the American people from health threats.

Frieden called the ACIP a model of transparency. “It involves not just doctors and nurses but professional organizations, community groups and consumers,” he said. “Every single deliberation of that committee is open to the public. All of the materials are available on the Web. We’ve always found that sunlight is a good disinfectant.”

The panel issues widely followed guidelines, including recommendations for childhood vaccines that form the basis for vaccination requirements set by public schools. The recommendations include when a vaccine should be given, the number of doses needed, the amount of time between doses, and precautions and possible allergic reactions.

Frieden said, “When it comes to parents vaccinating children, the vast majority vaccinate their children on time and per physician recommendations.”

Trump's meeting with Kennedy has alarmed scientists, public health officials and professional medical organizations that say putting a conspiracy theorist in a position of authority on the issue would be dangerous. Instead of turning to reputable experts to learn about vaccine safety, they said, Trump is relying on people who spread misinformation.

“President-elect Trump has some doubts about the current vaccine policies, and he has questions about it,” Kennedy told reporters Tuesday after meeting with Trump.

A Trump spokeswoman said no final decision has been made about the commission. But Kennedy sent an email Wednesday to members of an environmental group that he leads saying he would take a temporary leave from his senior attorney position at the group to serve for one year as chair of what he called a new commission on vaccine safety and scientific integrity.

“The President-elect called me last Wednesday to ask me directly to chair the commission,” Kennedy wrote in his email. “I agreed to serve as Chairman for a one year term. At this point, I'm awaiting to see the transition team's detailed proposal before making my commitment final.” He added that the panel “is still way up in the air.”

The current federal advisory committee on immunizations consists of 15 voting experts who are responsible for making vaccine recommendations. No members are federal government employees. The health and human services secretary chooses them after a rigorous screening that includes an application, interview and nomination process. Fourteen of the members have expertise in vaccinology, immunology, pediatrics, internal medicine, nursing, family medicine, virology, public health, infectious diseases and/or preventive medicine, according to the CDC. One member is a consumer representative.

Vaccine manufacturers and lobbying groups do not provide financial or other support to the committee or its members.

The committee also works with 30 highly regarded professional health and medical organizations, including the American Academy of Pediatrics and the American Academy of Family Physicians.

ACIP holds three meetings each year at CDC headquarters in Atlanta to make vaccine recommendations. Members present findings and discuss research and scientific data related to vaccine effectiveness and safety, clinical trial results, and manufacturer's labeling or package insert information.

Over the years, the number of vaccines included in the recommended immunization schedule for children under 18 years old has increased from six in 1964 to 16, according to a 2014 CDC report. The recommended immunization schedules for children, adolescents and adults are updated and approved by the ACIP and professional organizations.

According to the committee, for each vaccine recommendation, the panel reviews:

The safety and effectiveness of the vaccine when given at specific ages. Only vaccines licensed by the Food and Drug Administration are recommended, and vaccine manufacturers must conduct rigorous studies to show that a vaccine is safe and effective at specific ages

The severity of the disease.

The number of children who get the disease if there is no vaccine.

How well a vaccine works for children of different ages.

The meeting with Kennedy follows one that Trump had last summer with Andrew Wakefield, who published a fraudulent study claiming a link between autism and the measles-mumps-rubella virus and launched the modern anti-vaccine movement.

“Presidents and presidents-elect aren’t supposed to know everything,” Paul Offit, a professor of pediatrics and director of the Vaccine Education Center at the Children's Hospital of Philadelphia, wrote in a column for the Daily Beast. 

But they are supposed to surround themselves with people who can direct them to the experts, which in this case shouldn’t include conspiracy theorists promoting discredited beliefs. Donald Trump is a lucky man. He is in a position to avail himself of the best information this country has to offer. He should do it. Because if he doesn’t, we will continue to see children suffer and die from vaccine-preventable diseases — children who are counting on their leaders to make the right decisions.”

Sarah Kaplan contributed to this report.

Read more:

Donald Trump and Robert F. Kennedy Jr. just made pediatricians' jobs a lot harder

New data shows a deadly measles complication is more common than thought

Scientists don't have a decade to find a Zika vaccine. They need volunteers now.

7 things about vaccines and autism that the movie “Vaxxed” won't tell you