Inoculating the planet from Covid-19 presents an unprecedented logistical challenge like none we’ve seen before. Mobilizing for a world war may be the closest comparison, but in this case, the enemy is invisible and everywhere.

Some of the vaccines require super-cold storage at virtually all points along the journey until they reach someone’s upper arm. And the vaccines are primarily being produced in wealthier countries, though the need, especially now, is greatest in the poorest.

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