Any suggestions for changing the FDA-authorized dosing or schedules of these vaccines is premature and not rooted solidly in the available evidence, according to FDA Commissioner Dr. Stephen Hahn and Dr. Peter Marks, PhD, director of the FDA's Center for Biologics Evaluation and Research.

"Without appropriate data supporting such changes in vaccine administration, we run a significant risk of placing public health at risk, undermining the historic vaccination efforts to protect the population from COVID-19," Hahn and Marks wrote.

As of now, the available data continue to support the use of two specified doses of each authorized vaccine at specified intervals, according to Hahn and Marks.

"We know that some of these discussions about changing the dosing schedule or dose are based on a belief that changing the dose or dosing schedule can help get more vaccine to the public faster," they wrote. "However, making such changes that are not supported by adequate scientific evidence may ultimately be counterproductive to public health."

Hahn and Marks said that they remain committed to making decisions based on data and science.

"Until vaccine manufacturers have data and science supporting a change, we continue to strongly recommend that health care providers follow the FDA-authorized dosing schedule for each COVID-19 vaccine," Hahn and Marks wrote in the statement.