Laid low by a Covid-19 outbreak that’s decimated passenger demand, airlines will be the workhorses of the attempt to eradicate it, hauling billions of vials to every corner of the globe In cooled warehouses on the fringes of Frankfurt airport, Deutsche Lufthansa AG is preparing its depleted fleet for the gargantuan task of airlifting millions of doses of the vaccines meant to end the global pandemic. Lufthansa, one of the world’s biggest cargo carriers, began planning in April in anticipation of the shots that Pfizer Inc. to Moderna Inc. and AstraZeneca Plc are developing in record time. A 20-member task force is at work devising how to fit more of the crucial payload onto the airline’s 15 Boeing Co. 777 and MD-11 freighters, along with hold space in a vast passenger fleet now flying at just 25% of capacity. “The question is how we scale it up,” said Thorsten Braun, who leads Lufthansa’s part in the global effort. Laid low by a Covid-19 outbreak that’s decimated passenger demand,...