As COVID-19 Vaccines Draw Nearer to Approval, All Face Distribution Challenges
As Pfizer and Moderna prepare to file for Emergency Use Authorization for their promising COVID-19 vaccines in the coming weeks, they will face unprecedented distribution challenges – in Pfizer’s case the need to hold the doses at super-cold temperatures.
In addition to super-cold holding, the Pfizer/BioNTech vaccine requires two doses, as does the Moderna and AstraZeneca vaccines, but Johnson & Johnson’s vaccine candidate can be held at normal freezer temperatures and requires just a single dose, giving it a clear advantage in terms of logistics. Vaccine candidates from other developers, such as Moderna and Sanofi, can be held at normal refrigeration temperatures.
AstraZeneca’s two-dose vaccine candidate, AZD1222, must also be held at super-cold temperatures, but the company has said it intends to add a final ingredient that will allow vaccine vials to be held at regular fridge temperature when the vaccine nears approval.
HHS believes that the limited supplies that will be initially available will help limit the logistical challenges. “In the first phase of vaccine distribution, Operation Warp Speed (OWS) anticipates having a limited supply of COVID-19 vaccines to distribute, which should ease initial concern over potential long-term storage of vaccine doses,” an HHS spokesperson told FDAnews.
Although the Pfizer/BioNTech vaccine must be stored at -94 degrees Fahrenheit (-70 Celsius) and can last for 10 days in dry ice, the vaccine’s shelf life can be extended by up to 15 days by adding fresh ice and it can then be held under normal refrigeration temperatures for a further five days.
|Holding Temperature||Doses Needed|
|Pfizer/BioNTech||-94 degrees Fahrenheit (-70 Celsius)||2|
|Moderna||-4 degrees Fahrenheit (-20 Celsius)||2|
|AstraZeneca||Currently super-cold, but AstraZeneca plans to add a final ingredient to allow for regular refrigeration.||2|
|Johnson & Johnson||-4 degrees Fahrenheit (-20 Celsius)||1|
A Pfizer spokesperson told FDAnews that the company plans to address the temperature limitation by shipping “direct from our facilities to points-of-use designated by the U.S. government … in order to reduce additional handling and reduce transportation time.”
HHS confirmed that “the intent is to distribute vaccines to state-identified locations when vaccine administration can quickly follow, meaning that frequently the vaccines will be administered before needing to use storage other than the containers the vaccines are shipped in.”
HHS added that distribution centers can “repack opened shipping containers with dry ice multiple times for an additional 15 days.” But HHS acknowledge that vaccine shipments facing the risk of expiration would have to be moved quickly to “sites with larger demand.”
Pfizer yesterday announced a pilot distribution program in New Mexico, Rhode Island, Tennessee and Texas to assess how distribution would work given their differing sizes and their need to distribute coronavirus vaccines to varied urban and rural areas. But the company made clear that the four states in the pilot will not be receiving vaccine doses ahead of other states (see related story).
Pfizer said it anticipates initial vaccination locations will include vulnerable “priority groups” and places such as “hospitals, outpatient clinics, community vaccination locations and pharmacies,” with U.S. distribution straight from Kalamazoo, Mich., or a Pfizer facility in Pleasant Prairie, Wisc.
The shipping and distribution challenges in wealthy nations will be magnified for less developed countries that may lack the necessary medical infrastructure for vaccine storage and distribution.
“Our supply chain is practical and reliable, and we will be able to ship directly to vaccination centers [across the world] within one to three days,” Pfizer said. The company has “designed a special thermal shipper” to accommodate “a range of storage conditions at the point of use based on those site’s capabilities,” the company said.
Pfizer claims this means, if available, a vaccine could be stored for up to six months in an ultra-low temperature freezer. The drugmaker also notes that thermal shippers are equipped with GPS-enabled temperature monitoring allowing tracking of vaccine temperature fluctuations in real-time.
Other vaccine developers, such as Johnson & Johnson and Sanofi, claim their vaccines can be distributed using existing global networks, mitigating potential distribution hurdles and potentially enabling wider access to vaccines. — Jason Scott