In-Depth: Two ways the U.S. could accelerate vaccinations

Experts weigh the impact of syringes and 'pooling'
Posted at 7:12 PM, Apr 07, 2021

SAN DIEGO (KGTV) -- Millions of Americans are getting a COVID-19 vaccine every day but pharmacy groups say there are still ways the U.S. could maximize its supply and prevent viable doses from going to waste.

Although some states are on pace to vaccinate all willing adults by mid-summer, others are proceeding at a much slower rate that could stretch until late 2021. Experts say two efforts to improve efficiency could free up hundreds of thousands of shots per day, allowing the U.S. to export unneeded doses to other countries in desperate shape.

In December, pharmacists across the country noticed vials of both the Pfizer and Moderna vaccines were overfilled, offering extra doses to providers with the skill and the right syringes to extract them.

All of the Pfizer kits now shipped by the federal government contain 1 mL syringes to ensure providers can extract a sixth dose out of the five-dose vial. Most of these syringes have high-efficiency plungers designed to minimize waste -- what are called “low dead-volume” syringes -- that allow vaccinators to draw a seventh dose.

However, the Moderna kits still largely contain standard 3 mL syringes.

While it’s not impossible to extract extra shots out of the 10-dose Moderna vial with the larger syringe, “it's just easier, it's more accurate to measure using a smaller device when possible,” said Michael Ganio, director for pharmacy practice and quality at the American Society of Health-System Pharmacists.

“Of course in a public health emergency, we're doing everything we can to immunize everyone as quickly and safely as possible, but under ideal circumstances we would use 1 mL syringes for everyone,” he said.

The inconsistent availability of 1 mL syringes, particularly ones with the low dead-volume feature, has sent some vaccinators scrambling to buy them for themselves and forced others to let bonus doses go to waste.

“There's not enough of all one device to go around for everyone right now,” Dr. Ganio said.

Groups like U.S. Pharmacopeia have published guides to help vaccinators get the most out of whatever tools they have.

“Getting as many shots in arms is more important than ever, now that we’re in a race against virus variants,” said Farah Towfic, PharmD, the project lead for USP.

But regardless of syringe supply, Ganio says there’s one policy change that could make a huge difference overnight. ASHP and other pharmacy groups have pressed the Food and Drug Administration to allow providers to aggregate leftover vaccine from multiple vials into one dose, a technique called pooling.

“Under specific conditions we think it's possible to combine that half dose with a half dose from another vial and you can increase the number of patients that you're immunizing by about 10 percent,” Ganio said.

An extra 10 percent would make about 300,000 more doses available right away, each day.

The FDA has resisted calls to allow pooling because of concerns about cross-contamination, explained Dr. Christian Ramers of Family Health Centers of San Diego.

“These vaccines are preservative free, so a fungus or bacteria or something could get in there and you don't want to be mixing and have the possibility of contamination,” he explained.

Pharmacy groups say pooling has been done for years with other vaccines, and they argue it can be done safely with simple precautions. One such precaution is to ensure vials are pooled less than six hours after they are opened.

“That six-hour window really does not allow enough time for any bacteria to grow,” Ganio said.

In the coming weeks, Ganio notes the supply of doses will not be the limiting factor; it will be the capacity of providers to administer the shots.

But until then, pooling vials and providing the right syringes could speed up the U.S. vaccination effort, potentially allowing the country to share more vaccines in parts of the world that are struggling to contain variants.