Coronavirus: FDA opposes vaccine dose deviations

After an official floated the idea of only giving patients a partial dose of Moderna’s vaccine, the FDA stepped in to clarify.

The Food and Drug Administration (FDA) are urging physicians to follow the authorized dosing schedules for COVID-19 coronavirus vaccines.

The directive came after Moncef Slaoui, chief adviser as part of Operation Warp Speed, said on the Jan. 3 episode of Face the Nation that possibly giving a half-dose of the Moderna vaccine could be just as effective and lead to more people being vaccinated with the current supply.

According to a transcript of the interview, Slaoui says that the administration was in discussions with Moderna and the FDA on this possible route.

FDA Commissioner Stephen M. Hahn, MD, and Peter Marks, MD, director of the FDA’s Center for Biological Evaluation and Research, responded to that speculation in a release late in the evening Jan. 4 saying that changes in dosing schedules requires more study and that the data in Moderna and Pfizer’s EUA submissions are being misinterpreted.

“In the phase 3 trials, 98% of participants in the Pfizer-BioNTech trial and 92% of participants in the Moderna trial received two doses of the vaccine at either a three- or four-week interval, respectively,” the release says. “Those participants who did not receive two vaccine doses at either a three-or four-week interval were generally only followed for a short period of time, such that we cannot conclude anything definitive about the depth or duration of protection after a single dose of vaccine from the single dose percentages reported by the companies.”

Eschewing the FDA dosing schedule can lead to patients believing they are more immune to the disease than is the case which can lead to them altering their behavior and taking unnecessary risks, according to the release.

“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,” the release says. “However, making such changes that are not supported by adequate scientific evidence may ultimately be counterproductive to public health.”