On the second consecutive day of a record surge in  Covid-19 cases, South Korea reported 621,328 coronavirus cases on Thursday. With one in every 20 people testing positive over the past seven days, the weeklong surge of Omicron variant-led cases has already surpassed all its previous waves. South Korea, which responded to past swells with all-out efforts to track, test and isolate the infected, is now responding with a collective shrug and pushing ahead with plans to ease social distancing measures, relax border restrictions and learn to live with the virus’s risk, even as it is experiencing some of the highest per-person infection rates anywhere in the world.