he U.S. might have more doses of Pfizer’s COVID-19 vaccine than it thought.

While each Pfizer vial is supposed to hold five doses of the first vaccine authorized for emergency use by the Food and Drug Administration, Politico was first to report on Wednesday that pharmacists have discovered some vials may have extra doses, potentially adding to the country’s supply.

“The amount of vaccine remaining in the multidose vial after removal of 5 doses can vary, depending on the type of needles and syringes used,” a Pfizer spokesperson told USA TODAY in a statement. “At this time, we cannot provide a recommendation on the use of the remaining amount of vaccine from each vial. Vaccinators need to consult their institution’s policies for the use of multidose vials.”

The FDA has authorized hospital pharmacists to use the extra doses while the agency works with Pfizer officials to “determine the best path forward.”

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A vial of the COVID-19 candidate vaccine developed by BioNTech and Pfizer is displayed at the headquarters in Puurs, Belgium.
“At this time, 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,” FDA spokesperson Monique Richards told USA TODAY in a statement.

Pharmacists must throw away any extra amount of the vaccine if it does not consist of the 0.3 mL needed for a full dose, Pfizer said. The remaining amount “must never” be combined with the vaccine from another vial.

The Pfizer vaccine, green-lighted by the FDA on Dec. 11, was developed in less than a year, a fraction of the time it would usually take as researchers worldwide frantically sought an antidote to a virus discovered in China in December 2019.