FDA Encourages Use of Extra Doses of Pfizer COVID Vaccine Vials

Kerry Dooley Young

December 23, 2020

Editor's note: Find the latest COVID-19 news and guidance in Medscape's  Coronavirus Resource Center.

US regulators last week gave a clear direction to pharmacists about using excess supply found in what were meant to be five-dose vials of the Pfizer-BioNTech COVID-19 vaccine.

Responding to queries from pharmacists, the US Food and Drug Administration (FDA) has encouraged the use of excess material in vials. The agency included a note on the excess supply in a frequently asked questions (FAQ) document posted on its website.

"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, pending resolution of the issue," the agency said.  "However, since the vials are preservative free, it is critical to note that any further remaining product that does not constitute a full dose should not be pooled from multiple vials to create one."

Initially, there was reluctance to try to squeeze extra doses from the excess product seen in vials of the Pfizer-BioNTech vaccine, said Anna Dopp, PharmD, senior director for clinical guidelines and quality improvement for the American Society of Health-System Pharmacists (ASHP).

"Our members are used to trying to optimize the use of injectable medications, and so seeing overfill is something that they are accustomed to," Dopp told Medscape Medical News. "But they're rule followers. So without hearing officially from the FDA, they were hesitant to act upon seeing those that overfill and the potential for an extra dose."

To spread the message about the potential for the extra doses of the Pfizer-BioNTech vaccine, Doran Fink, MD, PhD, deputy director in FDA's division of vaccines and related products applications, on December 20 gave a public presentation on this guidance. He spoke during a meeting of the Advisory Committee on Immunization Practices (ACIP) of the Centers for Disease Control and Prevention.

"Based on the volume that is achieved upon dilution of the vaccine that is provided in the vial, typically six doses are obtainable," Fink said. "Sometimes with very skilled preparation, a seventh dose might be obtained as well."

Fink said the FDA is working with Pfizer to update fact sheets about the vaccine. The goal is to make the most of every dose that can be obtained, he said.

In a statement emailed to Medscape, Pfizer spokesman Steven Danehy said the Pfizer-BioNTech vials contain enough vaccine for at least five doses.

"The amount of vaccine remaining in the multidose vial after removal of five doses can vary, depending on the type of needles and syringes used plus the amount of diluent added," Danehy said. "If the amount of vaccine remaining in the vial cannot provide a full additional dose, the vial and any excess volume must be discarded."

Pfizer continues to closely coordinate with FDA on further guidance for healthcare providers, he said.

ASHP's Dopp said she does not expect there to be this kind of excess product found with Moderna's COVID-19 vaccine, which is distributed in 10-dose vials.

ASHP anticipated that there would be questions about the potential for extra doses of Moderna's vaccine, given the experience with the Pfizer-BioNTech shot, she said. ASHP asked Moderna officials about this and learned that the company already had done testing with pharmacists and nurses in terms of readying doses for delivery and checking how many doses each vial might provide. Based on this work, Moderna is not expecting there to be extra doses, Dopp said.

For more news, join us on Facebook and Twitter.  Have a tip for us? Contact us


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.