Alex Tabarrok points out that some health professionals have been surprised to discover they can get seven full doses of the new Pfizer COVID vaccine out of a vial that nominally contains five doses. Seven vs. five is a very big deal when you’re trying to vaccinate hundreds of millions of people as quickly as possible. The difference lies in the syringe: all syringes waste a bit of whatever is in them — this is called dead volume — but some are so well engineered that they waste much less. Using “low dead-volume” syringes can buy you 40 percent more doses in a vial, and Tabarrok says they don’t cost that much more. So far these special syringes are not a standard item in the kits HHS is sending out, but making and distributing more of these useful items is an innovation that could save many lives.