Pfizer lab found way to extract extra dose from vials

Beginning in August, a halfdozen researchers at a Pfizer lab in Massachusetts sat down with vials of experimental coronavirus vaccine to learn how to transform the “overfill” in every vial — an extra amount of liquid standard for injectable pharmaceuticals — into a precious sixth dose.

Over the next few months, they tested dozens of different combinations of syringes and needles, drawing out vaccine and squirting it into a beaker resting on a digital scale, repeating the experiments five to 10 times for each.

By Jan. 6, the work paid off. Pfizer won approval from the Food and Drug Administration to say its vials contained six doses instead of the five the agency had approved less than a month earlier with its Dec. 11 emergency authorization of the vaccine.

The shift gave regulatory approval for Pfizer to sell 20 percent more vaccine at a time of severe scarcity. It also permitted Pfizer to apply that additional dose to its government contracts.

But regulatory approval immediately collided with the fragilities of America’s medical supply chain and a shortage of equipment able to extract all six doses out of Pfizer’s vials.

The FDA approval of the bonus dose caught state regulators and health systems unprepared, creating a sudden demand for millions of specific syringes and adding to the confusion of the slow and uneven rollout of vaccine across the country.

The timeline outlined by two Pfizer executives to the Washington Post shows the company had been working on a solution to the sixth dose for months before hospital pharmacists independently discovered that each vial contained enough overfill for an extra shot.

The chain of events signals a lack of coordination between federal officials and the vaccine supplier that was first over the finish line, said Jesse Goodman, a former chief scientist at the FDA and the director of Georgetown University’s Center on Medical Product Access, Safety and Stewardship.

He noted that health providers were able to extract extra vaccine from vials during the H1N1 pandemic in 2009, so it was a known strategy to stretch supplies.

“I think this could have been anticipated. … It’s one more thing that was lost in the woodwork during the vaccine response,” he said. “If this problem had been identified and surfaced as part of the planning effort for vaccination, rather than suddenly ramping up production of these things in the last month, this is something that could have been done six months ago.”