Cracking the cold case

Our deliverance from pandemic life could be on the way, in the form of a COVID-19 vaccine. And when that deliverance arrives, it may come in something that resembles a pizza box.

In the U.S., Emergency Use Authorization (EUA) of two vaccine candidates is expected in the next few weeks. This is, of course, a tremendously important milestone – but in terms of getting vaccines to healthcare providers who can, in turn, immunize individual people in every community from COVID-19, approval is only step one. 

The next big hurdle is distribution and delivery: getting the vaccine-filled vials to locations around the country where they can be properly disseminated to the public. There are logistical problems that make this step more complicated than one might think, mostly due to the fact that the first vaccines likely to be approved must be kept at extremely cold – not frozen peas cold, but rather deep freeze, chiller-than-Antarctica – temperatures.   

To meet these logistical challenges head on, a core Walgreens team stays laser-focused on supporting our country’s vaccine program from start to finish. We spoke with a few of these experts to better understand the what, why and how of getting these desperately needed vaccines to communities across America.
 
Why so cold?
The first two vaccines expected to be approved by the Food and Drug Administration (FDA), from Pfizer and Moderna, are both “messenger RNA” (mRNA) vaccines. These use a different mechanism of action than other vaccines on the market, and contain enzymes that can break down very quickly.

Now, think about why food keeps longer in the freezer than in the fridge. The colder temperature slows the molecules in food from moving, as well as slowing enzyme activity. The same general concept applies here – except the vaccines need to be kept at much colder temperatures than your typical freezer to keep their active ingredients safe.

While both of the first vaccines likely to be approved by the FDA require very cold temperatures, “Pfizer’s requires storage between 70 to 80 degrees (Celsius) below zero, whereas Moderna’s needs to be kept at minus 15-25 degrees (Celsius),” says Jacqueline Pham, category manager, brand Rx & vaccine purchasing.  

Since both vaccines will be needed for the foreseeable future (as well as others currently in trials and development that may require cold storage), Walgreens has to consider the needs of both products.
 
Defending against defrosting 
Before we talk about how and where the vaccines will be stored and distributed, we have to think about how we’ll actually get the doses to our locations. This process is called the vaccine “cold chain”: the temperature-controlled supply chain that includes the full range of vaccine-related equipment and procedures, beginning with the manufacturer and ending with vaccine administration to the patient.

Walgreens is well-versed in handling vaccines due to our immunization services and the on-site flu shot clinics we run every year, but the extreme temperatures needed to handle these first COVID-19 vaccines, as well as the logistics of getting them safely to the first-phase recipients in offsite healthcare and long-term care facilities, requires special considerations.
 
And that’s where the “pizza boxes” come in. The Pfizer vaccine will be shipped to Walgreens in a thermal shipper filled with dry ice and temperature gauges, with the vaccine being packaged in a trays or “pizza boxes”, resembling those that typically carry America’s favorite takeout treat. Each tray contains a minimum of 195 vials (with 5 doses per vial or 975 doses), and up to five trays can be sent per thermal shipper.

The thermal shipper can be opened a maximum of 2 times per day for about 3 minutes each time. Every five days or so, team members will add new dry ice using cryogenic gloves. This extends the life of the thermal shipper for about 30 days, turning it into a short-term freezer solution.
One of the thermal shippers used for the vaccine. 

Around 100 hubs across the country will have a permanent ultra-cold freezer installed so our team members can safely transfer and store Pfizer’s COVID-19 vaccine into the designated freezers that keep the product at the right temperature. (In addition, hundreds of additional hubs will have dry ice storage capabilities which will also keep the vaccine at the proper temperatures.) 
 
“In these freezers, the vaccine can be stored up to six months,” says Dave Stauffer, director of immunizations, Walgreens. “But once thawed, it can only last in normal refrigeration for five days – and once you open and reconstitute a vial, the vaccines are only good for six hours. If the entire vial isn’t used in that six hour window, it becomes waste.”

Moderna’s vaccine, on the other hand, has its own set of guidelines to manage. Their product can be frozen in a typical pharmacy freezer for up to six months, refrigerated for 30 days, and kept at room temperature for 12 hours. But just like the Pfizer vaccine, once a vial is punctured the vaccine is on borrowed time - after six hours, it’s no longer viable.
 
From hub to spoke
As the vaccine manufacturers work to meet intense demand around the world, every single dose counts. Walgreens is using a hub and spoke model to ensure that the vaccines can be kept, transported and delivered safely.
 
“The Walgreens locations with cryogenic freezers and/or dry ice storage will act as the hubs,” says Vicki Yu, another member of Stauffer's team. “They’ll receive and hold the doses for the spoke stores. Team members at both the hub and spoke stores will then be able to access the vaccines, and will be directly involved in their administration at long-term care facilities as part of Phase 1 of Operation Warp Speed.”
 
“Having so many locations all over the country allowed us to strategically place the hubs, maximizing the location of doses to where patients are most in need, from a population perspective,” Stauffer adds. “This gives us the ability to provide coverage in underserved and rural locations, to help ensure that the entire population is protected.”

Pharmacy team members can come and pick up the vaccines at the hub stores, taking a carefully planned amount of doses – for example, enough for a specific site, or if there are multiple clinics near one location that will happen within a few days, they would be able to take doses to store for a short time in a normal pharmacy refrigerator.

The vaccine manufacturers are also giving instructions to Walgreens regarding transportation from hub to spoke to site, based on ongoing research studies, so contingency plans are constantly top of mind in case new equipment has to be procured quickly. For example, while still being reviewed, based on information currently available the Moderna vaccine must be transported in a frozen state to avoid any shaking of the vaccine as it thaws – something that the team must consider when planning for the roll-out.
 
The team doesn’t just think about freezers and transportation; they also focus on safety of the people involved in the supply chain. This means everything from providing team members three different kinds of gloves for handling the vaccines –  “these vials are cold; your hand can stick to them if you have any moisture on the skin,” Stauffer cautions – to keeping the stores dealing with dry ice (which can pose safety concerns) to a minimum.
 
An illustration of the interior of the “deep freeze” units which can store vaccines for up to six months.

Training is vital for anyone handling the vaccines, from beginning to end. Any time the temperature changes or shipments are being transferred from one container to another, or when a vial is opened, there is room for error. Walgreens’ safety teams developed a comprehensive, procedural guide on how to safely manage these processes.
 
Warming up to stay cool
With all the complexities of the cold chain, the Walgreens team has been in a constant state of learning, adapting and responding for the past few months.

“It’s an evolving story,” says Stauffer. “As the manufacturers are learning about the products, we're responding to that as well.”

That’s the advantage of being part of Walgreens Boots Alliance, a global company with local expertise, Yu points out. The team can lean on partners across geographies and functions to apply learnings, and combine that with on-the-ground experience.
 
“Because of our involvement with COVID testing back in the spring, we are able to leverage the processes that were set up in an even more rapid and ambiguous environment,” she says. “There were a lot of lessons learned from that experience, and we applied that knowledge to create our hub and spoke model.”
 
Ultimately, a safe, effective and well-managed vaccination program is what will get the country back on its feet. Fixing their eyes on this goal helps the team keep their cool while maintaining the cold chain for these first vaccines.   
 
 As Stauffer puts it, “This is our job, to make sure that the doses are going in people's arms, giving them that protection against COVID-19, and not going to waste.”