The Biden administration is facing controversy over its acceptance of Pfizer-BioNTech’s application to authorize the COVID-19 vaccine for children under 5 without showing completed clinical trial data, and officials are now scrambling to convince the public that the accelerated process is not sacrificing science.

Pfizer-BioNTech submitted part of its application to the Food and Drug Administration on Tuesday to authorize a 3-microgram-dose COVID-19 vaccine for children under five. The company had initially tested a two-dose regimen in children but announced in December that adding a third dose would be necessary to prompt an immune response. But the clinical trial data to support the authorization of a three-dose regimen is missing results from administering the third dose, causing concern that the agency is sacrificing science for expediency.