While the Western world tries to educate (not very successfully) part of its population about the safety of vaccines and the need to extend prevention campaigns, other regions face even bigger challenges—for example, getting vaccines to remote areas with proper refrigeration. Bill Gates has concentrated his resources on solving that problem, and the result is Indigo, a portable cooler that keeps vaccines within the ideal temperature range, without batteries or ice.
The Cold Chain Challenge
Bill Gates opens his presentation by sharing the story of a woman named Papa Blandine Mbwey. For a decade, Blandine's job has been to vaccinate children living in the most remote regions of the Democratic Republic of Congo, children who cannot reach the nearest clinic on their own. Many of Blandine's trips are on foot, but besides the distance, this vaccination hero faces another problem: the cold chain. Vaccines must be stored at a specific temperature—between 2 and 8 degrees Celsius, to be precise. If they get too warm, they are ruined. If they get too cold, the water inside them freezes and they may stop working. By the time Blandine reaches the children, the vaccines have traveled more than 8,000 kilometers, and although the cold chain could break at any moment, the critical points are the last two: the clinic that stores vaccines with very frequent power outages, and people like Blandine doing the transport. The great wildcard of portable refrigeration is ice, but it only lasts a short time. That's when Bill Gates appears with his device Indigo:
How Indigo Works
At first glance it looks like any other portable cooler, but Indigo's secret is inside. It has an insulated container with an extra layer that holds water at very low pressure, to the point that the liquid evaporates at 5 degrees Celsius. Once the system is activated, the water begins to evaporate and reduces the container's temperature to the level needed for vaccines. The movement of water to the outer layer happens at a specific rate, so cooling in general can last a long time—between 5 and 7 days. The only thing the user has to do to return the water to the beginning of its cycle (in other words, a "reset" of Indigo) is to heat its exterior.
MetaFridge: The Other Half of the Equation
Now, Indigo is only half the equation. The other half is represented by MetaFridge, a refrigeration system that keeps vaccines at the right temperature for up to five days. Bill Gates explains that MetaFridge's electronic design allows it to withstand power surges and periods of low voltage, classic problems of an unstable electrical grid. A screen informs users how long it can maintain cold, crucial data for activating generators at the exact moment or moving vaccines elsewhere. Gates said MetaFridge is already being manufactured by a Chinese company, and a new version with solar panels will hit the market soon. Indigo is still in the testing phase, but preliminary numbers are very encouraging: vaccinators could reach four times more people.
