Hospital pharmacists discovered Dec. 16 that some vials of Pfizer's COVID-19 vaccines that are supposed to hold five doses actually contain six or seven, The New York Times reported.
The discovery may mean the U.S. supply of the vaccine is more robust than previously thought, but it has also caused confusion over whether to use the extra doses or throw them out, since the extra doses weren't part of Pfizer's guidance.
Federal officials have to carefully track the number of vaccine doses to make sure there's enough for everyone who received an initial dose to receive a second dose three weeks later. The extra vials may complicate that effort, The Hill reported.
Northwell Health in New Hyde Park, N.Y., told the Times it estimated it had to throw out 15 to 20 doses of the vaccine while waiting on guidance from the state health department on what to do with them.
The FDA tweeted Wednesday evening saying that "given the public health emergency, FDA is advising that it is acceptable to use every full dose obtainable (the sixth, or possibly even a seventh) from each vial, pending resolution of the issue."
The agency said it's consulting with Pfizer on how to address the issue. It stated that pharmacists should not mix vaccines from multiple vials to create a full dose.
A Pfizer spokesperson said that the amount left over after the five doses may vary based on the type of syringe being used and the amount of diluting solution used by pharmacists preparing the vaccines, The Hill reported.