Vaccinators will be able to get one extra dose out of each vial of Moderna’s Covid-19 vaccine, and soon new vials that hold even more doses will become available. The changes were among those authorized by the FDA as the regulator and vaccine makers look for ways to get more doses into more arms.
The FDA said late Thursday the maximum doses available from a current vial of Moderna’s messenger RNA Covid vaccine is now 11, up from 10. The regulator also authorized new vials that hold between 13 and 15 doses each.
The actual number of doses available will depend on the type of syringe and needle used, so the FDA cautions that the total could be lower than the new authorized maximums. But Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, said the changes will help make more vaccine doses available.
“Ultimately, more vaccines getting to the public in a timely manner should help bring an end to the pandemic more rapidly,” Marks said in a prepared statement.
The FDA previously revised the maximum doses permitted for each vial of the Covid vaccine made by Pfizer and BioNTech. But for both mRNA vaccines, the regulator said that to avoid contamination, any vaccine remaining in a vial should not be pooled with remnants from other vials to create a full dose.
Cambridge, Massachusetts-based Moderna said it studied ways to add more doses to each vial as a way to address manufacturing bottlenecks, accelerate vaccine production, and reduce the need for consumable materials that are in high demand. The company said it expects to start shipping the new 15-dose vials in coming weeks.
The Moderna Covid vaccine authorized for emergency use is based on messenger RNA technology. It delivers genetic material with instructions for making the spike protein prominent on the surface of the novel coronavirus. Cells use those instructions to make copies of the spike protein, which prompts the immune system to produce antibodies that confer immunity. But the fragility of mRNA requires ultra-freezing temperatures as the vaccine makes its way through the supply chain.
New changes authorized for the Moderna vaccine extend to vaccination sites. Once removed from refrigeration, the FDA said the vaccines may be kept at room temperature for 24 hours, up from the 12 hours specified in the initial emergency authorization. Also, a punctured vial is now authorized for use for up to 12 hours, up from six hours. The Moderna vaccine comes ready for use and does not require any dilution once it reaches the proper temperature. That’s different than the Pfizer/BioNTech vaccine, which must be diluted with saline.
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