Pfizer's COVID-19 vaccine rollout could heat up after FDA clears warmer storage requirements

Pfizer and its German partner BioNTech have been scrambling to unshackle their COVID-19 vaccine Comirnaty from the cold chain. Now, the FDA has warmed to the idea, updating the shot's prescribing information to allow for storage above subzero temperatures.

Pfizer and BioNTech’s COVID-19 vaccine Comirnaty can now be stored and transported at standard pharmaceutical freezer temps for up to two weeks, provided the vials are undiluted and still frozen, the FDA said Thursday. The change could simplify deliveries of the vaccine, which previously needed to be kept at an icy minus 112 degrees to minus 76 degrees Fahrenheit. 

The change comes at a time when vaccine makers are hustling to boost supply and states are clamoring for more doses, but some locations, particularly in rural areas, lack the cold storage equipment needed to accept the Pfizer shot.

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The move will “help ease the burden of procuring ultra-low cold storage equipment for vaccination sites and should help to get vaccines to more sites,” Peter Marks, M.D., Ph.D., director of the FDA’s Center for Biologics Evaluation and Research, said in a release.

That boost could ease distribution outside the U.S., too, following concerns last year that Comirnaty’s cold chain requirements might hamstring rollouts in countries with less-developed healthcare systems.

Pfizer last week said it had supplied the FDA with data showing its shot remains stable between minus 13 degrees to 5 degrees F. The submission pulled in stability data from batches made over the past nine months of development, from those used to supply the earliest clinical trials through current commercial supply, Pfizer said in a release.

The company now says it plans to submit those data to other regulatory agencies, and future stability data could tee up a shelf life extension or usher in additional short-term storage temp adjustments, Pfizer said. 

Right now, the prescribing update doesn’t extend to thawed vials before dilution, which can be kept in the fridge for up to five days, or thawed and diluted vials, which can be held in the fridge or at room temperature for use within six hours, the FDA said.

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“We will continue to leverage our expertise to develop potential new formulations that could make our vaccine even easier to transport and use," Ugur Sahin, CEO of BioNTech, noted in a release. 

Improving distribution has been on the companies' radar since late last year. In November, Pfizer's chief scientist Mikael Dolsten told Business Insider the company was considering a next-generation formula to ease storage and shipping concerns. "For the COVID-19 disease, I think we'll roll out next year a vaccine in powder format," he said, adding that the new version "could be just for refrigeration." 

That work has now kicked off, a Pfizer spokesperson said via email. If successful, the company could roll out an easy-to-distribute, freeze-dried powder formulation in 2022. 

Last Summer, analysts raised flags about Comirnaty's cold chain constraints. SVB Leerink analysts in August warned that the temperatures needed to store mRNA vaccines would be "severely limiting" to distributors' ability to ship the shots and to clinics' ability to administer them to a wide range of patients. 

Concerns over Pfizer's shot prompted other mRNA vaccine players, such as Moderna and Germany's CureVac, to tout their shots' warmer storage needs. Moderna in November said its vaccine can be kept at 36 degrees to 46 degrees F for up to 30 days, and for up to 12 hours at room temperature. That same month, CureVac revealed its shot was stable for up to three months in the fridge and good for a full 24 hours at room temperature.