The vials of Pfizer's COVID-19 vaccine are supposed to contain five doses each—but, in a pleasant surprise, hospitals have discovered that there's actually enough in each vial for six or even seven doses. After a flurry of messages between pharmacists on message boards and Twitter, the FDA issued a statement Wednesday saying that, "given the public health emergency," every full dose left over in a vial can be used, the New York Times reports. However, it advised that remainders from multiple vials not be combined to make a full dose due to a risk of cross-contamination, the Washington Post reports. The FDA also said it is consulting with Pfizer on the issue and how to move forward. Politico reports such "overfill" is common as a guard against spills, but this appears to be more than pharmacists typically find left inside vials.
Pfizer says there's a uniform amount of vaccine in each vial, but that depending on the type of syringe used and how much diluting solution is used, the amount left could vary. It confirms it is consulting with the FDA and said it could not currently "provide a recommendation on the use of the remaining amount of vaccine from each vial," other than to advise those carrying out the vaccinations to consult local health authorities. Utah's health department, for example, initially advised for the overfill to be discarded, but now University of Utah officials say they will start using it following the FDA's statement. However, it's not as simple as it might sound: The vaccine supply has been carefully managed, so for anyone receiving one of the extra doses, there will also need to be enough available for them to get the necessary booster in three weeks. (More coronavirus vaccine stories.)