The Food and Drug Administration said on Monday that considerations of altering the coronavirus vaccine schedule are “premature.”
Currently, the two coronavirus vaccines that have received an emergency use authorization require two doses. For the Pfizer vaccine, the booster comes three weeks after vaccine administration. The Moderna vaccine requires the second dose four weeks after inoculation.
But in recent weeks, as the distribution of the vaccine has gone slower than expected, some have speculated on whether the booster dose should be used to inoculate others.
Data has shown that the two vaccines are at least 94% effective after the second dose is administered. So far, there is not enough data to estimate the effectiveness of a single dose, leaders from the FDA said.
“These are all reasonable questions to consider and evaluate in clinical trials,” FDA Commission Stephen Hahn and Center for Biologics Evaluation and Research Director Peter Marks said in a joint statement. “However, at this time, suggesting changes to the FDA-authorized dosing or schedules of these vaccines is premature and not rooted solidly in the available evidence. 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.”
As of Monday, there are 4.5 million Americans who have received their first dose of one of the two coronavirus vaccines. It was not until Monday that some Americans began receiving a second dose of the vaccine.
So far, there have been 15 million doses of the vaccine distributed. Leaders of Operation Warp Speed had estimated last month that 20 million doses of the vaccine would be distributed by the end of 2020.
But administering the vaccine has been challenging, with people declining the vaccine and its short shelf life once it is pulled from the freezer add to the snags.
But Marks and Hahn caution that foregoing the second dose of the vaccine could cause more harm than good without data to backup the effectiveness of the first dose.
“Using a single dose regimen and/or administering less than the dose studied in the clinical trials without understanding the nature of the depth and duration of protection that it provides is concerning, as there is some indication that the depth of the immune response is associated with the duration of protection provided,” they said. “If people do not truly know how protective a vaccine is, there is the potential for harm because they may assume that they are fully protected when they are not, and accordingly, alter their behavior to take unnecessary risks.”