Every year, over 1 million children die from diseases that are preventable with vaccines. The problem isn’t just that vaccines aren’t available. Even when they are, breakdowns in the refrigerated vaccine supply chain (aka the "cold chain")--which often occur in areas where power is unreliable--make them unusable.
Global Good, a collaboration between Bill Gates and Intellectual Ventures, is pilot-testing a possible solution: the Passive Vaccine Storage Device, dubbed the "super-thermos" by Gates. The device, which has been in the works since 2008 (when Gates first challenged Intellectual Ventures to tackle the problem), keeps vaccines between zero and eight degrees Celsius for 30 to 60 days, depending on outside temperatures and humidity. That’s a big deal in many parts of the developing world, where health officials often see cold storage devices that can keep vaccines fresh for five days at the absolute maximum.
As you might guess from Gates’s nickname for the device, the super-thermos was inspired by the humble coffee thermos. "It’s a super-insulated, double-walled dewar that holds the vaccine and ice in the middle in an inner bottle. A vacuum space separates it from the outer bottle, like a large coffee thermos," says Kurt Armbruster, the project’s leader. The device features many layers of insulation in the vacuum space--the same insulation technology used to protect spacecraft from high temperatures.
If health officials are going to spend big bucks for something--the device costs $1,100--they’ll want to know if it’s being used correctly. So Global Good built in sensors and SMS capabilities for officials to keep track of the super-thermos’s location, interior temperature, exterior temperature, how long it has been opened, and for how long.
There are three layers to the capabilities: a simple temperature monitoring system inside and outside the device that logs data every 15 minutes and can be monitored when health workers plug in a USB stick; an SMS antenna and SMS telemetry system that dials out to a local phone number every night at midnight and sends a summary of the day’s temperatures, location, and statistics about how long and when it has been opened; and a GPS sensor that allows officials to track where the units are at any given time. Every device comes with all the feature sets, though Global Good says it will probably sell the super-thermoses in a basic and "plus" version.
During pilot testing in Senegal, Global Good found the sensors to be extremely useful. If a health worker wasn’t using the device correctly, for example, Global Good could get in touch and have them retrained. In the future, that kind of monitoring will fall to ministries of health. "The ministry [in Senegal] is very interested in demonstrating that they have a reliable cold chain all the way to the end point," says Armbruster.
There have been challenges during pilot testing. "Some of our team members have very by-the-book methodology to engineering or science and don’t always take into account field conditions," says Armbruster. "When we go to the field, things that are obvious to us, like that we can make this hold for 30 days, have had to overcome skepticism. Things like 'Oh, we’ll just download the data from the Internet,' and [that people] don’t always have reliable cell service or air conditioning. It becomes a lot easier when engineers come with us and see the real-life conditions."
The Global Good team is already making some design tweaks based on user feedback. The clean-looking white design with blue handles is being replaced with a green design, because users associate the color green with pharmacies. Testers also requested that the device come with a lock, because vaccines are valuable.
Armbruster says the device is least useful in villages of 25,000 to 50,000 people, where it makes sense to have a large solar-powered or ice-lined fridge. And it won’t be particularly useful in places that have reliable power--say, a small clinic in downtown Lagos, Nigeria. But in smaller villages of 5,000 to 15,000 people, it’s more cost effective to have something like the Passive Vaccine Storage Device, which can be refreshed once a month when health workers come to get their paychecks and take care of business.
Global Good is gearing up for another pilot test in Senegal this August. After that, it has other pilots lined up in Ethiopia, Zambia, and possibly Haiti.