"It's more valuable than liquid gold, truth be told," said Melanie Massiah-White, chief pharmacy officer for Inova Health System, a nonprofit hospital network based in Northern Virginia.

"But ultimately, in aggregate, that adds up to a lot of doses that end up being wasted, and we're not allowed to use that additional vaccine.

Pharmacists at Inova Health, one of the largest hospital systems in the Washington, D.C., area, say they started noticing significant amounts of leftover vaccine in almost every vial, even after they used the additional sixth doses in Pfizer's vials.

The pharmacists found that with the vaccine left in the 80 vials, they could make 40 additional full doses.

That meant that on a typical vaccination day, when the hospital will typically give more than 4,000 shots, it could give an additional 400 vaccination shots with the same supply.

"If that vial is not used right away, then the risk of contamination is higher, because no preservative is contained in the vial," Ferreri said

Inova health officials say that all doses are used almost immediately at large vaccination clinics like theirs and that they already have protocols to protect against any type of cross-contamination

"We would use those doses within 60 minutes," Massiah-White said

"Ultimately, when there are enough vaccines, wasting some at the bottom won't matter," Jones said