Some of the shots now in late stages of testing must be stored at temperatures potentially as cold as minus 80 degrees Celsius, or minus 112 Fahrenheit, similar to conditions for transporting ice cream and steaks to supermarkets and eventually to people’s doorsteps.
Hospitals, pharmacies and physicians’ offices are expected to be vaccination sites, but they have few such specialized freezers. That is prompting a mad dash by logistics, public-health and drug-industry officials to cobble together a cold-storage supply chain that can deliver vaccines around the country without letting them become warm and ineffective.
To address concerns about equipment and storage capacity, hospitals are considering plans to buy special freezers. Logistics companies and other nontraditional health-care competitors are building facilities to house hundreds of mobile cold-storage units, known as freezer farms.
At least one drugmaker has created its own specialized container to keep vaccines cold for at least 10 days uninterrupted. Meanwhile, vaccine makers are studying whether their shots could be shipped at warmer temperatures to potential vaccination sites.
Vaccines are similar to dairy or meat products in that their chemical structures are maintained when they are kept within certain temperature ranges. Drug companies have lots of data on optimal temperatures for vaccines such as chickenpox and shingles. But given the breakneck pace of Covid-19 vaccine development, researchers lack the information about storage requirements that they would normally learn after clinical trials are completed.
A Covid-19 vaccine stored at ultracold temperatures would stress the supply chain because of the demands required for transportation and storage, said Chaun Powell, who leads disaster preparedness and response at Premier Inc., a major group-purchaser for U.S. hospitals, physician clinics and other places.
“When you think about getting this out to 300 million American adults, every logistical efficiency you can garner is going to help us with that,” he said. “It’s really about trying to figure out, how are we going to get it to those people…within an hour of their home?”
Vaccines are viewed by health and industry officials as key to stopping the spread of the new coronavirus that causes Covid-19. The most advanced are undergoing testing with clinical trials involving 30,000 people or more, and the U.S. government has begun planning for these vaccines’ potential distribution as soon as later this year.
Two leading Covid-19 vaccine candidates, from Pfizer Inc. and partner BioNTech SE, and from Moderna Inc., rely on a new gene-based technology called mRNA that requires the shots be stored at subzero temperatures. Both vaccines have been stored at ultracold temperatures, around minus 70 or minus 80 degrees Celsius.
Medications such as cell-based therapies also are shipped at ultracold temperatures, often using liquid nitrogen or dry ice. But doing so can be costly. And never have so many vaccines been shepherded so quickly.
Health and industry officials expect hospitals to be the sites where the first vaccines are administered to millions of health-care workers. But many hospitals don’t have the space or mechanical requirements to store vaccines at subzero temperatures, according to industry officials.
The lack of equipment means access to some vaccines might vary around the country. Pharmacies and clinics aren’t expected to become vaccination sites until a vaccine is authorized for the broader population, possibly next year.
“You have to target the vaccines to the location where the storage and handling facilities are available,” said Dr. William Schaffner, professor of preventive medicine and infectious disease at Vanderbilt University Medical Center. “It may be that every vaccine can’t be used in every location.”
Ultracold freezers aren’t common in hospitals because most drugs and vaccines don’t need them. The chickenpox vaccine is one of the few vaccines that needs to be stored frozen. Flu vaccines are refrigerated.
Because of their limited shelf life even while in cold storage, Covid-19 vaccines might need to be used within six months, a much smaller window than for other pharmaceuticals, according to experts.
“Hopefully the vaccines are going to be used as quickly as they’re made, and therefore cold-chain storage is only to get it where it’s needed, rather than stored for long periods,” said James Robinson, a consultant helping the Oslo-based Coalition for Epidemic Preparedness Innovations, which is financing coronavirus vaccine projects.
Philadelphia’s Jefferson Health hospital system should be able to store vaccines at minus 30 degrees Celsius but might have limited ultracold storage space, said Brian Swift, chief pharmacy officer. He said Jefferson, which expects to begin vaccinations with its 30,000 employees, anticipates purchasing at least 15 special freezers.
“Everyone’s going to be looking for these things,” he said. “We’re talking about high-end freezers that are not readily available, that have a limited supply chain. I am concerned about the availability of that.”
To ensure its vaccines remain frozen at minus 70 degrees Celsius, Pfizer created a temperature-controlled container about the size of a suitcase that can keep between 1,000 and 5,000 doses cold for 10 days before requiring more dry ice. Once thawed, the vials can be refrigerated for as long as two days.
Most commercial containers preserve temperatures for just a few days, and Pfizer wanted to offer hospitals temporary cold storage, said Tanya Alcorn, the drugmaker’s vice president of supply chain. “We don’t want them to feel rushed,” Ms. Alcorn said.
Earlier this year, Moderna stored its vaccine at minus 70 degrees Celsius in preparation of clinical trials. Since then, it has done further study and now plans to ship the shots at minus 20, the company said. Once thawed, the vaccine can remain refrigerated for a week.
Some other Covid-19 vaccines in human testing don’t require ultracold temperatures. Johnson & Johnson’s experimental vaccine is expected to be shipped commercially at standard refrigeration, a spokesman said. AstraZeneca PLC, which co-developed a vaccine with University of Oxford researchers, expects its vaccine to need refrigeration, a spokesman said.
Meanwhile, physicians’ offices, pharmacies and other places Americans go for routine health care are poised to be sites for Covid-19 vaccinations early next year, and public-health and industry officials are worried that many of them lack ultracold freezing capabilities. Pfizer’s own containers might not work for smaller clinics or pharmacies that won’t be administering thousands of doses, public-health officials said.
The containers “are not going to be something that can go to your corner pharmacy or your local family physician,” said Dr. Kelly Moore, associate director of immunization education at the Immunization Action Coalition.
Pfizer said it also is working on a smaller container to ship its vaccines. It is also developing a powder version of its vaccine, known as a lyophilized formulation, that can be stored at warmer temperatures, but it might not be ready until the end of 2021.
Moderna, Dr. Moore said, will ship its vaccine in minimum 100-dose packages through McKesson Corp., which the government has tapped as a central distributor of Covid-19 vaccines.
A CVS spokesman said that its locations can accommodate refrigeration and freezing storage requirements for many of the experimental Covid-19 vaccines and that it is in talks with the Trump administration about vaccine administration.
A McKesson spokesman said the wholesaler will ship Covid-19 vaccines requiring refrigeration to minus 20 Celsius. Since at least 2018, the Irving, Texas-based wholesaler has worked with Cryoport Inc., which provides temperature-controlled shipments for pharmaceutical companies. Cryoport already uses technology that can keep livestock-animal vaccines at minus 196 degrees for about a month, said Mark Sawicki, who leads Cryoport’s legacy logistics division.
Cryoport is in discussions with other parties to potentially help distribute Covid-19 vaccines, Mr. Sawicki said.
United Parcel Service Inc. plans by October to finish construction of its freezer farms filled with mobile freezer units in Louisville, Ky., and the Netherlands to serve as stopover points during distribution or while awaiting regulatory decisions, said Wes Wheeler, president of UPS Healthcare.
He said the freezers, which can hold as many as 48,000 vials each, can be configured to hold a vaccine at between minus 85 and minus 20 degrees Celsius.
—Elaine Chen contributed to this article.
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