A federal agency and medical industry organization both warned health professionals not to immunize young children against the deadly disease on Aug. 23.

The U.S. Food and Drug Administration (FDA) and American Academy of Pediatrics (AAP) want every physician to urgently stop administering the Pfizer-BioNTech vaccine to children under 12 years-old.

FDA warns recently granting full approval does not mean the jab can be used for off-label purposes in anyone outside of the recommended age range of 16 and older. This is because the dosage for younger patients is much smaller, and there are no existing safety data for that demographic.

“The vaccine is being distributed under provider agreement by the U.S. government through the Centers for Disease Control and Prevention,” FDA Acting Commissioner Janet Woodcock said according to Fox News. “There are many considerations that would pertain to off-label prescribing for the recipient and so forth.”

Woodcock urged doctors not to routinely prescribe the vaccine without directions. This is because children are not just “small adults,” and this is a common misperception that health professionals realized “time and time again.”

“We do not have data on proper dose, nor do we have full data on safety in children younger than what is in the emergency use authorization,” she said according to MedPage Today. “That would be a great concern that people would vaccinate children.”

Meanwhile, University of Alabama pediatric infectious disease expert David Kimberlin revealed the licensed dose for people 12 and older is 30 micrograms. However, the dosage currently studied in children aged 5 to 11 is a “third of that” at 10 micrograms, and just 3 micrograms for those aged under 5.

“We cannot have physicians writing for the approved 30 microgram dose to be used in someone under 12,” he said according to the publication. “It is a much higher dose than what is being studied.”

The professor revealed the lower dose was only chosen for “immunogenicity and reactogenicity” reasons.

“We are going to have to get the word out that we should not be simply taking the Pfizer vaccine approved for adults, and putting it in the arms of those under 12,” he said.

Mayo Clinic researchers believes any clinician prescribing for off-label indications effectively administers doses, or dosage forms, is doing so without FDA approval.

AAP similarly warned against unauthorized use of the vaccine in children under 12.

“The clinical trials for the COVID-19 vaccine in children ages 11 years-old and younger are underway, and we need to see the data from those studies before we give this vaccine to younger children,” AAP President Lee Savio Beers said in a statement.

AAP’s infectious disease committee revealed there are significant risks in giving young children the same dosage as adults.

“We do not want individual physicians to be calculating doses and dosing schedules one-by-one for younger children, based on the experience with the vaccine in older patients,” Chairwoman Yvonne Maldonado said in the statement. “We should do this based on all of the evidence for each age group, and for that we need the trials to be completed.”