The throughput is the issue. If you can run the same number of vials in manufacturing process and gain a 50 percent increase in doses, it is a victory!
From the New York Times:
"Moderna has discussed the possible change of the number of doses in vials with the F.D.A. but has not yet submitted manufacturing data to support it, people familiar with the discussions said. Federal regulators may be receptive to the idea of more doses in each vial, but could balk at the notion of a 50 percent increase.
"The industry standard has long been 10 doses per vial, and federal regulators may be concerned that the extra punctures by needles of the rubber covering of the vial and the time required to extract more doses could increase the risk of contaminating the vaccine with bacteria. Moderna’s proposal to the F.D.A. for the dose increase was first reported by CNBC.
"Packing more vaccine into each Moderna vial is one of a number of options White House and health officials are exploring as they push to expand production before the spring, when officials are expecting a renewed surge of infections from emerging variants of the virus.
"The maker of the other federally approved vaccine, Pfizer, is unable to increase the amount of vaccine in its vials because its manufacturing is geared toward a particular size of vial that can hold only about six doses. But Moderna’s vial is big enough to hold more than the 10 doses now allowed."
