The European Union medicines watchdog said Thursday that German company BioNTech has applied for clearance in the 27-nation bloc to administer up to six doses of its COVID-19 vaccine from each vial, instead of the five doses currently approved. 

In an email to The Associated Press, the European Medicines Agency said that BioNTech, which developed its vaccine together with U.S. drugmaker Pfizer, has "submitted a request for change" which will be reviewed by the agency's human medicines committee "in the shortest possible timeframe."

It said that if the committee establishes that six doses can be consistently extracted from each vial of vaccine, it will recommend changing the authorization that clears the vaccine for use in EU nations.

In a written statement, Pfizer said its vials contain enough vaccine for at least five doses and the amount remaining can vary depending on the type of needles and syringes used.

"Decisions regarding label updates and/or other temporary approvals regarding dose preparation and administration belong to local health authorities," the company said.

German weekly Der Spiegel first reported this week that BioNTech has asked European regulators to change the conditions of approval to allow doctors to use excess vaccine in the vials to draw a sixth dose if possible, rather than tip the leftovers away after five as currently required.

This could result in hundreds of thousands of additional doses in Germany alone during the first quarter, Spiegel reported.

Regulators in the United States, Switzerland and the UK already allow up to six doses of 0.3 milliliters each to be drawn from vials.

"The vaccine is manufactured with enough volume for five doses," the UK regulator MHRA said in an email. "However, it is normal for some vials to contain a slight excess volume, and in some cases this could allow a full sixth dose to be extracted."

"However, care needs to be taken to ensure a full 0.3 ml dose can be administered to the individual," it added. "Where this cannot be achieved when diluted as recommended, the vial and its contents should be discarded after the fifth dose has been extracted."

Mixing leftovers from multiple vials is forbidden by all regulators.

German Health Minister Jens Spahn on Wednesday backed the idea of extracting additional doses if possible.

BioNTech intentionally fills the vials with more vaccine than necessary to ensure that even inexperienced doctors can get at least five doses out of them.