As of writing this article, multiple COVID-19 vaccines have been approved for distribution and are being administered across the world. The speed of vaccine development has been astounding. It took just six weeks from start to producing a vaccine candidate, the fastest in medical history. On December 2nd, 2020, Pfizer’s vaccine became the first fully-tested immunization to be approved for emergency use. Vaccines usually take years to develop, for comparison the fastest before COVID-19 was the mumps vaccine in the 1960s which took 4 years (see The lightning-fast quest for COVID vaccines — and what it means for other diseases).

This astounding speed isn’t a miracle. The vaccine development was built on a foundation made by decades of advanced scientific research and investment in infrastructure. Key enablers of vaccine development for COVID-19 included genome sequencing, mRNA platforms, global communications networks, and organizational bodies like the International Coalition of Medicines Regulatory Authorities.

However, vaccine development is just one piece of an effective response to a global pandemic. It doesn’t matter if we’ve developed the perfect vaccine if we can’t manufacture the number of vaccines needed, distribute the vaccines to the places where it’s needed, and administer the vaccines to the people who need it.

In this post, I’ll be focusing specifically on the distribution of vaccines and how the Internet of Things (IoT) plays a critical role.

What is the Cold Chain?

Pfizer’s vaccine must be kept at –94℉ (–70℃) and Moderna’s vaccine must be kept at –4℉ (–20℃), otherwise the vaccines will spoil. To distribute these vaccines across broad geographies while keeping them at the right temperature necessitates an effective cold chain. But what is the “cold chain” exactly?

The cold chain refers to the overall system for distributing products that need to be kept at low temperatures. This applies to vaccines, but also applies to other goods like chemicals and the meat you buy at your grocery store. Goods are often distributed using several different transportation technologies over the course of their journey. 

For example, a vaccine might be driven via truck from the manufacturing facility to a nearby airport, fly via plane, get loaded on to another truck, then ultimately be delivered to a pharmacy and stored until it’s ready to be administered to someone.

There are actually three cold chains, classified by how stringent the requirements are for temperature:

1. Refrigerated Chain: between 36℉ to 46℉ (2℃ to 8℃)
2. Frozen Chain: below –4℉ (–20℃)
3. Ultracold Chain: below –94℉ (–70℃)
   

The Pfizer vaccine therefore requires the Ultracold Chain, but one study estimated that only ~25 countries have the ultralow infrastructure. To help address these infrastructure shortcomings, Pfizer has designed a box to manage the temperature in transit, using dry ice to maintain the –94℉ (–70℃) for up to 10 days. These boxes also implement IoT technology to monitor location and temperature in real-time. We’ll take a deeper look at the role of IoT in the cold chain shortly, but first let’s take a look at the non-IoT standard.

Keeping the Cold Chain Cold

Spoilage of cold goods isn’t a new challenge, approximately 25 percent of shipped vaccines are compromised due to poor temperature management, according to a 2019 report from the International Air Transport Association.

This necessitates two objectives:

1. Improve temperature management to reduce instances of spoilage.
2. Identify when temperature thresholds are broken (called a “temperature excursion) so that spoiled vaccines won’t be administered to patients.
   

Today, the standard is to use Temperature Monitoring Devices (TMDs), and the CDC recommends a specific type called a “digital data logger” (DDL). Unlike a simple minimum/maximum thermometer, which only shows the coldest and warmest temperature reach in a unit, a DDL provides detailed information on all temperatures recorded at preset intervals (minimum recommended interval is every 30 minutes).

The use of TMDs helps with objective #2 above, identifying temperature excursions. However, this approach has several shortcomings:

• Localized: The only way to know that a temperature excursion has occurred is to be physically local to the TMD. Some DDLs have alarms that will trigger when a temperature excursion occurs, but if no one is nearby no one will hear the alarm.
• Data Segregation: It’s hard to aggregate data across many different DDLs because that data needs to be collected and aggregated manually to generate insights. For example, if you wanted to compare temperature data captured by many DDLs to get insights into the effects of transit on temperature, you would have to manually pull the data from all the DDLs and supplement with other data like transit times, transit method, etc..
• No Position Data: DDLs capture temperature, but usually don’t capture location through the journey. This means DDLs can’t be used to improve logistics and routing, only temperature.
• Highly Manual: Even with DDLs, there are a lot of manual processes that must be followed in conjunction. For example, if a temperature excursion event occurs, staff must manually notify the vaccine coordinator, manually label exposed vaccines, and manually record info such as who noticed the temperature excursion, length of time affected, inventory of affected vaccines, and what actions were taken.
• Reactive: DDLs can only react to temperature excursions after they’ve occurred, at which point it may already be too late.

The Role of IoT in the Cold Chain

The Internet of Things (IoT) is fundamentally about making the location and status of assets knowable remotely and in real-time. The effective implementation of IoT in the cold chain can therefore help to solve both of the above objectives (improve temperature management and identify temperature excursions) while addressing the shortcomings of standard TMDs and DDLs.

At a high level, implementing IoT technology means that the location and temperature of vaccines can be transmitted wirelessly and automatically. This has the following benefits, in contrast to the shortcomings listed above:

• Globalized: Information and alerts can be sent to anywhere on the planet, provided there’s an internet connection. Even if no one is in physical proximity to hear an alarm, alerts can be pushed to smartphones or other systems to notify people of temperature excursions.
• Data Aggregation: Since data needs to be sent via internet connection anyways, it’s easy to aggregate data from many vaccines shipments/storage containers. This data can be automatically augmented by other data sources to generate insights from data analytics and/or machine learning. For example, if there are common patterns to temperature readings before a temperature excursion occurs.
• Position Data: A GPS sensor can be included to provide position data in addition to temperature data. According to this source, 50 percent of temperature excursions occur on airlines and in airports. Position data can supplement temperature data to validate whether this is true and whether there are particular stages (e.g. a certain airport) where temperature excursion events are more likely.
• Highly Automated: Many manual processes can be automated, for example staff would no longer need to manually notify the vaccine coordinator (it could be triggered automatically), and info about the temperature excursion could be automatically captured and recorded. This frees medical staff to focus on helping patients.
• Proactive: With the data aggregation mentioned above, it may become possible to predict temperature excursions before they occur. Commons patterns prior to temperature excursions can be identified and trigger alerts. If a freezer gets unplugged, a shipping box gets left cracked open, or the temperature regulator breaks, someone can address the issue proactively and prevent vaccine spoilage.
  

What IoT Tech is Used in the Cold Chain?

There is no one-size-fits-all solution in IoT. The particular technology used needs to fit the needs of the use case in which IoT is being implemented.

Pfizer states that it is using “GPS-enabled thermal sensors with a control tower that will track the location and temperature of each vaccine shipment across their pre-set routes, 24 hours a day, seven days a week.” Additional info on the particular tech used isn’t available, so I’ll make some guesses.

One possibility is that the GPS-enabled thermal sensors also come equipped with a Bluetooth radio. Bluetooth is great for low bandwidth, short range, low power applications. Pfizer’s shipping boxes would collect location data via GPS and temperature data with the thermal sensors, and then communicate using Bluetooth to a local gateway (the “control tower” mentioned). This local gateway would then use cellular or WiFi (perhaps even satellite) to send location and temperature data from multiple shipping boxes over the internet to where it’s needed.

The advantage of this approach is that it cuts down on the power needs of the boxes (since Bluetooth consumes little power). To cut down power needs further, the GPS sensor could be in the gateway itself, since each box would need to be in close proximity to the gateway anyways. The disadvantage of this approach is that boxes need to be in close proximity to a gateway. As soon as a box leaves the range of a gateway, such as if it’s being transported directly and individually rather than as part of a larger shipment with many boxes, then it can’t communicate.

A second possibility is that the GPS-enabled thermal sensors don’t have Bluetooth radios, but each have their own cellular and/or Wifi radios. This way, no intermediate gateway is needed and each box can communicate individually as long as there’s a cellular or WiFi connection.

The advantage of this approach is that boxes can be shipped individually and still tracked. This opens a wider variety of shipping possibilities, including direct shipment, local cross-docking, and local warehousing. The disadvantage of this approach is high energy needs of the GPS-enabled enabled thermal sensors, which would mean shorter battery life. Plus, higher costs to maintain the solution since a cellular connection is an expensive, ongoing cost.

Those are just two possibilities, but they reflect the high level possibilities and tradeoffs for cold chain monitoring with IoT.

Conclusion: IoT Adoption Accelerating

The biggest barrier to widespread adoption of IoT generally and for the cold chain specifically has been cost and reliability. When it’s expensive and unreliable to attach IoT devices to vaccine shipments and storage freezers, it makes more sense to use passive data loggers and manual processes. But the costs of IoT solutions is dropping drastically, and the pandemic has accelerated the need for real-time monitoring of shipments and storage because the industry standard of 25% vaccine spoilage can’t be afforded in the fight against COVID-10.

The pandemic has accelerated many trends that were already occurring, and the implementation of IoT in the cold chain is yet another example.