They were not the only spies at work. Russia's premier intelligence service, the S.V.R., targeted vaccine research networks in the United States, Canada and Britain, espionage efforts that were first detected by a British spy agency monitoring international fiber optic cables.

Iran, too, has drastically stepped up its attempts to steal information about vaccine research, and the United States has increased its own efforts to track the espionage of its adversaries and shore up its defenses.

In short, every major spy service around the globe is trying to find out what everyone else is up to.

The coronavirus pandemic has prompted one of the fastest peacetime mission shifts in recent times for the world's intelligence agencies, pitting them against one another in a new grand game of spy versus spy, according to interviews with current and former intelligence officials and others tracking the espionage efforts.