Vaccines like to be kept cool, none more so than the Pfizer candidate for Covid-19, which has to be deep-frozen. And that’s going to be an issue for developing countries – and for rural areas in the developed world.
The “cold chain” is just one of the challenges in distributing vaccines worldwide.
There are plenty of others: decisions about priority populations and databases to keep track of who’s received what vaccine, where and when. Additionally, different vaccines may have more or less efficacy with different population groups; and governments will need PR campaigns to persuade people that vaccines are safe.
But the logistics of transporting and storing vaccines – getting them from the factory gate to the patient’s arm – are critical. And as most vaccines are likely to require two doses, the whole chain needs must be repeated within weeks.
The Pfizer-BioNTech vaccine needs to be kept at around -70 degrees Celsius (-94 degrees Fahrenheit) while it’s transported. That’s 50 degrees Celsius colder than any other vaccine currently used.
Moderna says its vaccine can be kept in freezers typically available in pharmacies, and in a refrigerator for 30 days. But there are likely to be fewer doses of the Moderna vaccine than of the Pfizer’s available over the next year.
Phase 3 trials have shown both vaccines to be around 95% effective but the results haven’t yet been reviewed by regulators.
On Wednesday, the CEO of BioNTech, the German biotech company partnering with Pfizer, acknowledged the issue of temperature control.
“We are working on formulation which could allow us to ship the vaccine even maybe at room temperature,” Ugur Sahin told CNN. “We believe that in the second half of 2021 we will have come up with a formulation which is comparable to any other type of vaccine.”
But in the meantime US Health and Human Services Secretary Alex Azar believes the Moderna candidate is “more flexible” for settings like a local pharmacist. Pfizer’s, he said Monday, would be better suited to “big institutional vaccination, say a whole hospital setting, several nursing homes at once.”
Pfizer plans to ship up to 1.3 billion doses next year, requiring a lot of dry ice (carbon dioxide in solid form at around -78 degrees Celsius), and a lot of isothermic boxes. The boxes will hold up to 975 vials (4,875 doses) and can be refilled with dry ice for up to 15 days of storage.
Pfizer is testing the supply chain in four US states. Its CEO, Albert Bourla, said Wednesday he has “zero concerns” about the cold chain requirements.
But shipping such a vaccine can pose big challenges. Dr. Jarbas Barbosa, assistant director of the Pan American Health Organization, told CNN that “the rural and the urban areas in any country in the world are not ready to manage this vaccine today.”
“So, who is prepared in the world? No one.”
One issue is the availability of dry ice.
The Compressed Gas Association says carbon dioxide production capacity in the US and Canada is about 30,000 tons a day and is confident its members can meet demand for dry ice. It says that vaccine supply-chain officials believe less than 5% of dry ice production will be needed to support ultra-cold storage of Covid-19 vaccines in the United States and Canada.
Others in the industry expect bottlenecks. Several dry ice producers in the US told CNN they’ve already had offers for their entire output. Buddy Collen at Reliant and Pacific Dry Ice told online publication GasWorld: “We are in scramble mode trying to manipulate our production plants.”
Sam Rushing, president of Florida-based Advanced Cryogenics, told CNN there are already regional shortages in the US.
The main problem, Rushing says, is fewer vehicles on the road during the pandemic, meaning lower production of ethanol, from which carbon dioxide is a byproduct. European ethanol production has also fallen sharply this year.
US officials are confident enough dry ice will be available. Paul Ostrowski, director of supply, production and distribution for Operation Warp Speed, told CNN last week that courier UPS had pledged to “provide dry ice reshipments throughout all of America upon demand.”
But Rushing cautions that dry ice is not very user-friendly and can be hazardous if stored improperly, especially in a confined space. The Federal Aviation Administration classifies it as hazardous cargo.
Peter Gerber, CEO of Lufthansa Cargo, told CNN that the need for dry ice “clearly reduces also the transport capacity because if you have to load more ice you can’t load so much vaccine. And of course the procedures have to be very special in order to ensure that it always has this degree of coldness.”
US courier DHL is adapting distribution plans according to each vaccine’s specifications. David Goldberg, CEO of Global Forwarding US for the company, says “there’s a restriction on the amount of dry ice used on an aircraft – typically 500-1,000 kilos depending on a number of factors.”
Once they arrive, Pfizer vials can be stored at between 2 and 8 degrees Celsius for up to five days before deteriorating. Pfizer says it has developed a “just-in-time system which will ship the frozen vials direct to the point of vaccination.” It will also monitor the temperature of every box being shipped.
Julie Swann, an expert in supply chains at North Carolina State University, says that large hospital systems, which often have ultra-cool freezers, may have a role as distribution hubs. But not all US states have them; Hawaii said last week none of its hospitals had such freezers.
Breaking down shipme