Almost exactly a year ago, as the world was shutting down in the face of a terrifying new disease and as we watched news reports out of Italy and New York with growing horror, airline CEOs the world over were looking ahead to the crucial summer travel season and assuming travel would be at a standstill. But by May last year, many thought the lockdowns and quarantines had slowed Covid's relentless onslaught and spoke of "green shoots" (remember those?) as people yearned for their summer holidays. And traffic did return, but so did the disease.