One of the 12 labors of Hercules, according to ancient lore, was to destroy a nine-headed monster called the Hydra. The challenge was that when Hercules used his sword to chop off one of the monster’s heads, two would grow back in its place. He therefore needed an additional weapon, a torch, to vanquish his foe. There are parallels between this legend and our three-years-and-counting battle with SARS-Cov-2, the virus that causes Covid-19. Every time scientists have thought they’d subdued one strain of the virus — be it alpha, beta,…
