The Delta Variant Is a Grave Danger to the Unvaccinated

Lineage B.1.617.2, now known as the Delta variant, was first detected in India, in December, 2020. An evolved version of sars-CoV-2, Delta has at least a dozen mutations, including several on its spike protein that make it vastly more contagious and possibly more lethal and vaccine-resistant than other strains. In India, the Delta variant contributed to the most devastating coronavirus wave the world has seen so far; now, it has been detected in dozens of countries, including the United States. In the U.S., it accounts for a minority of cases—but it is rapidly outcompeting other...