Stresses of strains: emerging coronavirus variants

It is no surprise that more-transmissible coronavirus variants are cropping up. We ask how worrisome the strains found in Britain and South Africa are. American authorities have lodged a landmark case against Walmart for its role in the country’s worsening opioid crisis—a problem with clearly more than one cause. And dealing with the pile of unused vacation days from 2020.For full access to print, digital and audio editions of The Economist, subscribe here www.economist.com/intelligenceoffer