As pharmacists began vaccinations using the Pfizer vaccine some of them discovered that it was possible to extract a 6th or even 7th dose from a standard 5-dose vial. Where were the extra doses coming from? The fortuitous discovery was not due to over-filling. The vials contained just 5 doses when using standard syringes. But some of the vaccine distribution sites had access to low dead-volume syringes, syringes that leave less vaccine trapped between the plunger and needle — the “dead volume” — after a shot is given. Thus, less vaccine was wasted in the syringe and more available for putting into arms using the low dead-volume syringes.
This is quite remarkable. Increasing vaccine supply by 20% by building more factories could cost billions. We should do that, it would be worth it. But in this case, we managed to increase supply by at least 20% use a relatively inexpensive redesign of the syringe. What this indicates is the importance of thinking along the entire supply chain for opportunities for optimization.
The catch? Not all syringes provided by Operation Warp Speed and Pfizer are low dead-volume syringes so not every vaccine distribution site is getting the extra doses. We do need to invest more in the syringe supply chain.